Expandable intervertebral fusion device

ABSTRACT

The present invention provides an expandable fusion device capable of being installed inside an intervertebral disc space to maintain normal disc spacing and restore spinal stability, thereby facilitating an intervertebral fusion. The fusion device described herein is capable of being installed inside an intervertebral disc space at a minimum to no distraction height and for a fusion device capable of maintaining a normal distance between adjacent vertebral bodies when implanted.

CROSS-REFERENCE

This application claims the benefit of U.S. Provisional Application Nos.62/444,663, filed Jan. 10, 2017, 62/471,206 filed Mar. 14, 2017, and62/481,565 filed Apr. 4, 2017; the entire contents of which isincorporated herein by reference.

BACKGROUND

The present disclosure relates to medical devices and methods, and morepreferably relates to the apparatus and method for promoting anintervertebral fusion, and more particularly relates to an expandablefusion device capable of being inserted between adjacent vertebrae tofacilitate the fusion process.

A common procedure for handling pain associated with intervertebraldiscs that have become degenerated due to various factors such as traumaor aging is the use of intervertebral fusion devices for fusing one ormore adjacent vertebral bodies. Generally, to fuse the adjacentvertebral bodies, the intervertebral disc is first partially or fullyremoved. An intervertebral fusion device is then typically insertedbetween neighboring vertebrae to maintain normal disc spacing andrestore spinal stability, thereby facilitating an intervertebral fusion.

There are a number of known conventional fusion devices andmethodologies in the art for accomplishing the intervertebral fusion.These include screw and rod arrangements, solid bone implants, andfusion devices which include a cage or other implant mechanism which,typically, is packed with bone and/or bone growth inducing substances.These devices are implanted between adjacent vertebral bodies in orderto fuse the vertebral bodies together, alleviating the associated pain.

However, there are challenges associated with the known conventionalfusion devices and methodologies. For example, present methods forinstalling a conventional fusion device may require that the adjacentvertebral bodies be distracted to restore a diseased disc space to itsnormal or healthy height prior to implantation of the fusion device. Inorder to maintain this height once the fusion device is inserted, thefusion device is usually dimensioned larger in height than the initialdistraction height. This difference in height may make it difficult fora surgeon to install the fusion device in the distracted intervertebralspace.

As such, there exists a need for a fusion device capable of beinginstalled inside an intervertebral disc space at a minimum to nodistraction height and for a fusion device capable of maintaining anormal distance between adjacent vertebral bodies when implanted.

One of the most common post-operative complications of intervertebralfusion surgery is intervertebral graft or cage subsidence which areminimized or mitigated by using an intervertebral cage or graft of alarger footprint. This is often difficult because to minimize the traumaand morbidity associated with spine surgery, it is often advantageous toutilize the smallest surgical access corridor possible to achieve thegoals of surgery. As such there exists a need for a fusion devicecapable of being inserted through a relatively small surgical corridorand capable to then be expanded to a larger footprint suitable to resistsubsidence.

The present device preferably is capable of meeting both of thesecriteria—being able to be inserted at a minimum to minimal or nointervertebral distraction and at a minimum width through a relativelysmall surgical corridor to then be expanded and maintained at a largerfootprint suitable for resisting subsidence and at a greater heightsuitable for the goal of decompressing the neural elements andmaintaining the intervertebral height as well as desirable alignment ofthe adjacent vertebral bodies. At least some of these objectives will bemet by the exemplary embodiments disclosed herein.

DESCRIPTION OF THE BACKGROUND ART

8,568,481; 8,926,704; 9,474,625; 9,138,328; 9,445,918; 2016/0317315;2016/0324654; US20170056200A1; U.S. Pat. Nos. 9,801,734; 9,795,493;9,717,601; 6,821,298; US20110035011A1; U.S. Pat. Nos. 9,445,918;9,480,574; 6,176,882; 8,105,382; 8,568,481; US20160302940; U.S. Pat.Nos. 9,561,116; 9,278,008.

SUMMARY

Optionally, in any embodiment, the present disclosure provides anexpandable fusion device capable of being inserted at a minimum to nointervertebral distraction and at a minimum width through a relativelysmall surgical corridor to then be expanded and maintained at a largerfootprint suitable for resisting subsidence and at a greater heightsuitable for the goal of decompressing the neural elements andmaintaining the intervertebral height as well as desirable alignment ofthe adjacent vertebral bodies.

In one embodiment, the fusion device includes a proximal wedge, a distalwedge, a first ramp, a second ramp, a third ramp, a forth ramp, a firstendplate, a second endplate, a third endplate, a fourth endplate, anactuator and a retention member designed to constrain the linear motionof the actuator relative to the proximal wedge. The actuator capable ofdrawing the proximal wedge and the distal wedge together or apart fromeach other, forcing the first ramp away from the fourth ramp and forcingthe second ramp away from the third ramp and also forcing the first rampaway from or toward the second ramp and forcing the third ramp away fromor toward the fourth ramp, to result in moving the first endplate, thesecond endplate, the third endplate and the fourth endplate outwardlyfrom each other and into an expanded configuration.

A first aspect provided herein is an expandable fusion device forimplantation between two adjacent vertebrae, the device comprising: anactuator comprising a drive feature and an longitudinal axis; a wedgeassembly coupled to the actuator; a ramp assembly slidably coupled withthe wedge assembly; an upper endplate assembly slidably coupled with theramp assembly; and a lower endplate assembly slidably coupled with theramp assembly.

Optionally, in any embodiment, the device has a width comprising anexternal width of at least one of the upper endplate assembly and thelower endplate assembly. Optionally, in any embodiment, the device has aheight comprising an external distance between the upper endplateassembly and the lower endplate assembly. Optionally, in any embodiment,actuation of the drive feature by a first number of actuations in afirst actuation direction increases the width without increasing theheight. Optionally, in any embodiment, actuation of the drive feature bya second number of actuations beyond the first number of actuations inthe first actuation direction increases at least one of the height andthe width.

Optionally, in any embodiment, the first number of actuations is about0.5 actuations to about 10 actuations. Optionally, in any embodiment,the first number of actuations is at least about 0.5 actuations.Optionally, in any embodiment, the first number of actuations is at mostabout 10 actuations. Optionally, in any embodiment, the first number ofactuations is about 0.5 actuations to about 1 actuations, about 0.5actuations to about 1.5 actuations, about 0.5 actuations to about 2actuations, about 0.5 actuations to about 2.5 actuations, about 0.5actuations to about 3 actuations, about 0.5 actuations to about 3.5actuations, about 0.5 actuations to about 4 actuations, about 0.5actuations to about 5 actuations, about 0.5 actuations to about 6actuations, about 0.5 actuations to about 8 actuations, about 0.5actuations to about 10 actuations, about 1 actuations to about 1.5actuations, about 1 actuations to about 2 actuations, about 1 actuationsto about 2.5 actuations, about 1 actuations to about 3 actuations, about1 actuations to about 3.5 actuations, about 1 actuations to about 4actuations, about 1 actuations to about 5 actuations, about 1 actuationsto about 6 actuations, about 1 actuations to about 8 actuations, about 1actuations to about 10 actuations, about 1.5 actuations to about 2actuations, about 1.5 actuations to about 2.5 actuations, about 1.5actuations to about 3 actuations, about 1.5 actuations to about 3.5actuations, about 1.5 actuations to about 4 actuations, about 1.5actuations to about 5 actuations, about 1.5 actuations to about 6actuations, about 1.5 actuations to about 8 actuations, about 1.5actuations to about 10 actuations, about 2 actuations to about 2.5actuations, about 2 actuations to about 3 actuations, about 2 actuationsto about 3.5 actuations, about 2 actuations to about 4 actuations, about2 actuations to about 5 actuations, about 2 actuations to about 6actuations, about 2 actuations to about 8 actuations, about 2 actuationsto about 10 actuations, about 2.5 actuations to about 3 actuations,about 2.5 actuations to about 3.5 actuations, about 2.5 actuations toabout 4 actuations, about 2.5 actuations to about 5 actuations, about2.5 actuations to about 6 actuations, about 2.5 actuations to about 8actuations, about 2.5 actuations to about 10 actuations, about 3actuations to about 3.5 actuations, about 3 actuations to about 4actuations, about 3 actuations to about 5 actuations, about 3 actuationsto about 6 actuations, about 3 actuations to about 8 actuations, about 3actuations to about 10 actuations, about 3.5 actuations to about 4actuations, about 3.5 actuations to about 5 actuations, about 3.5actuations to about 6 actuations, about 3.5 actuations to about 8actuations, about 3.5 actuations to about 10 actuations, about 4actuations to about 5 actuations, about 4 actuations to about 6actuations, about 4 actuations to about 8 actuations, about 4 actuationsto about 10 actuations, about 5 actuations to about 6 actuations, about5 actuations to about 8 actuations, about 5 actuations to about 10actuations, about 6 actuations to about 8 actuations, about 6 actuationsto about 10 actuations, or about 8 actuations to about 10 actuations.Optionally, in any embodiment, the first number of actuations is about0.5 actuations, about 1 actuations, about 1.5 actuations, about 2actuations, about 2.5 actuations, about 3 actuations, about 3.5actuations, about 4 actuations, about 5 actuations, about 6 actuations,about 8 actuations, or about 10 actuations.

Optionally, in any embodiment, the second number of actuations is about0.5 actuations to about 10 actuations. Optionally, in any embodiment,the second number of actuations is at least about 0.5 actuations.Optionally, in any embodiment, the second number of actuations is atmost about 10 actuations. Optionally, in any embodiment, the secondnumber of actuations is about 0.5 actuations to about 1 actuations,about 0.5 actuations to about 1.5 actuations, about 0.5 actuations toabout 2 actuations, about 0.5 actuations to about 2.5 actuations, about0.5 actuations to about 3 actuations, about 0.5 actuations to about 3.5actuations, about 0.5 actuations to about 4 actuations, about 0.5actuations to about 5 actuations, about 0.5 actuations to about 6actuations, about 0.5 actuations to about 8 actuations, about 0.5actuations to about 10 actuations, about 1 actuations to about 1.5actuations, about 1 actuations to about 2 actuations, about 1 actuationsto about 2.5 actuations, about 1 actuations to about 3 actuations, about1 actuations to about 3.5 actuations, about 1 actuations to about 4actuations, about 1 actuations to about 5 actuations, about 1 actuationsto about 6 actuations, about 1 actuations to about 8 actuations, about 1actuations to about 10 actuations, about 1.5 actuations to about 2actuations, about 1.5 actuations to about 2.5 actuations, about 1.5actuations to about 3 actuations, about 1.5 actuations to about 3.5actuations, about 1.5 actuations to about 4 actuations, about 1.5actuations to about 5 actuations, about 1.5 actuations to about 6actuations, about 1.5 actuations to about 8 actuations, about 1.5actuations to about 10 actuations, about 2 actuations to about 2.5actuations, about 2 actuations to about 3 actuations, about 2 actuationsto about 3.5 actuations, about 2 actuations to about 4 actuations, about2 actuations to about 5 actuations, about 2 actuations to about 6actuations, about 2 actuations to about 8 actuations, about 2 actuationsto about 10 actuations, about 2.5 actuations to about 3 actuations,about 2.5 actuations to about 3.5 actuations, about 2.5 actuations toabout 4 actuations, about 2.5 actuations to about 5 actuations, about2.5 actuations to about 6 actuations, about 2.5 actuations to about 8actuations, about 2.5 actuations to about 10 actuations, about 3actuations to about 3.5 actuations, about 3 actuations to about 4actuations, about 3 actuations to about 5 actuations, about 3 actuationsto about 6 actuations, about 3 actuations to about 8 actuations, about 3actuations to about 10 actuations, about 3.5 actuations to about 4actuations, about 3.5 actuations to about 5 actuations, about 3.5actuations to about 6 actuations, about 3.5 actuations to about 8actuations, about 3.5 actuations to about 10 actuations, about 4actuations to about 5 actuations, about 4 actuations to about 6actuations, about 4 actuations to about 8 actuations, about 4 actuationsto about 10 actuations, about 5 actuations to about 6 actuations, about5 actuations to about 8 actuations, about 5 actuations to about 10actuations, about 6 actuations to about 8 actuations, about 6 actuationsto about 10 actuations, or about 8 actuations to about 10 actuations.Optionally, in any embodiment, the second number of actuations is about0.5 actuations, about 1 actuations, about 1.5 actuations, about 2actuations, about 2.5 actuations, about 3 actuations, about 3.5actuations, about 4 actuations, about 5 actuations, about 6 actuations,about 8 actuations, or about 10 actuations.

Optionally, in any embodiment, actuation of the drive feature by asecond number of actuations beyond the first number of actuations in thefirst actuation direction increases both the height and the width.Optionally, in any embodiment, actuation of the drive feature by asecond number of actuations beyond the first number of actuations in thefirst actuation direction increases the height without increasing thewidth.

Optionally, in any embodiment, the width of the device reaches an apexonce the drive feature is actuated by at least the first number ofactuations. Optionally, in any embodiment, the height of the devicereaches an apex once the drive feature is actuated by at least the firstand second number of actuations.

Optionally, in any embodiment, actuation of the drive feature in thefirst actuation direction by at least the first number of actuationsincreases the height of the device by about 30% to about 400%.Optionally, in any embodiment, actuation of the drive feature in thefirst actuation direction by at least the first number of actuationsincreases the height of the device by at least about 30%. Optionally, inany embodiment, actuation of the drive feature in the first actuationdirection by at least the first number of actuations increases theheight of the device by at most about 400%. Optionally, in anyembodiment, actuation of the drive feature in the first actuationdirection by at least the first number of actuations increases theheight of the device by about 30% to about 50%, about 30% to about 75%,about 30% to about 100%, about 30% to about 125%, about 30% to about150%, about 30% to about 175%, about 30% to about 200%, about 30% toabout 250%, about 30% to about 300%, about 30% to about 350%, about 30%to about 400%, about 50% to about 75%, about 50% to about 100%, about50% to about 125%, about 50% to about 150%, about 50% to about 175%,about 50% to about 200%, about 50% to about 250%, about 50% to about300%, about 50% to about 350%, about 50% to about 400%, about 75% toabout 100%, about 75% to about 125%, about 75% to about 150%, about 75%to about 175%, about 75% to about 200%, about 75% to about 250%, about75% to about 300%, about 75% to about 350%, about 75% to about 400%,about 100% to about 125%, about 100% to about 150%, about 100% to about175%, about 100% to about 200%, about 100% to about 250%, about 100% toabout 300%, about 100% to about 350%, about 100% to about 400%, about125% to about 150%, about 125% to about 175%, about 125% to about 200%,about 125% to about 250%, about 125% to about 300%, about 125% to about350%, about 125% to about 400%, about 150% to about 175%, about 150% toabout 200%, about 150% to about 250%, about 150% to about 300%, about150% to about 350%, about 150% to about 400%, about 175% to about 200%,about 175% to about 250%, about 175% to about 300%, about 175% to about350%, about 175% to about 400%, about 200% to about 250%, about 200% toabout 300%, about 200% to about 350%, about 200% to about 400%, about250% to about 300%, about 250% to about 350%, about 250% to about 400%,about 300% to about 350%, about 300% to about 400%, or about 350% toabout 400%. Optionally, in any embodiment, actuation of the drivefeature in the first actuation direction by at least the first number ofactuations increases the height of the device by about 30%, about 50%,about 75%, about 100%, about 125%, about 150%, about 175%, about 200%,about 250%, about 300%, about 350%, or about 400%.

Optionally, in any embodiment, actuation of the drive feature in thefirst actuation direction by at least the first and the second number ofactuations increases the width of the device by about 14% to about 150%.Optionally, in any embodiment, actuation of the drive feature in thefirst actuation direction by at least the first and the second number ofactuations increases the width of the device by at least about 14%.Optionally, in any embodiment, actuation of the drive feature in thefirst actuation direction by at least the first and the second number ofactuations increases the width of the device by at most about 150%.Optionally, in any embodiment, actuation of the drive feature in thefirst actuation direction by at least the first and the second number ofactuations increases the width of the device by about 14% to about 20%,about 14% to about 30%, about 14% to about 40%, about 14% to about 50%,about 14% to about 60%, about 14% to about 70%, about 14% to about 80%,about 14% to about 100%, about 14% to about 120%, about 14% to about140%, about 14% to about 150%, about 20% to about 30%, about 20% toabout 40%, about 20% to about 50%, about 20% to about 60%, about 20% toabout 70%, about 20% to about 80%, about 20% to about 100%, about 20% toabout 120%, about 20% to about 140%, about 20% to about 150%, about 30%to about 40%, about 30% to about 50%, about 30% to about 60%, about 30%to about 70%, about 30% to about 80%, about 30% to about 100%, about 30%to about 120%, about 30% to about 140%, about 30% to about 150%, about40% to about 50%, about 40% to about 60%, about 40% to about 70%, about40% to about 80%, about 40% to about 100%, about 40% to about 120%,about 40% to about 140%, about 40% to about 150%, about 50% to about60%, about 50% to about 70%, about 50% to about 80%, about 50% to about100%, about 50% to about 120%, about 50% to about 140%, about 50% toabout 150%, about 60% to about 70%, about 60% to about 80%, about 60% toabout 100%, about 60% to about 120%, about 60% to about 140%, about 60%to about 150%, about 70% to about 80%, about 70% to about 100%, about70% to about 120%, about 70% to about 140%, about 70% to about 150%,about 80% to about 100%, about 80% to about 120%, about 80% to about140%, about 80% to about 150%, about 100% to about 120%, about 100% toabout 140%, about 100% to about 150%, about 120% to about 140%, about120% to about 150%, or about 140% to about 150%. Optionally, in anyembodiment, actuation of the drive feature in the first actuationdirection by at least the first and the second number of actuationsincreases the width of the device by about 14%, about 20%, about 30%,about 40%, about 50%, about 60%, about 70%, about 80%, about 100%, about120%, about 140%, or about 150%.

Optionally, in any embodiment, the actuator has a distal end and aproximal end. Optionally, in any embodiment, at least a portion of thedistal end comprises a first thread feature. Optionally, in anyembodiment, at least a portion of the proximal end comprises a secondthread feature. Optionally, in any embodiment, the proximal endcomprises the drive feature. Optionally, in any embodiment, at least oneof the first thread feature and the second thread feature comprise athread disposed externally around the actuator. Optionally, in anyembodiment, at least one of the first thread feature and the secondthread feature has an opposite threading direction.

Optionally, in any embodiment, the wedge assembly comprises a distalwedge and a proximal wedge. Optionally, in any embodiment, actuation ofthe drive feature in the first direction converges the distal wedge andthe proximal wedge toward one another. Optionally, in any embodiment,the distal wedge comprises a third thread feature, and wherein the thirdthread feature is threadably coupled to the first thread feature.Optionally, in any embodiment, the proximal wedge comprises a fourththread feature, and wherein the fourth thread feature is threadablycoupled to the second thread feature. Optionally, in any embodiment, thethird thread feature comprises a thread disposed internally within thedistal wedge. Optionally, in any embodiment, the fourth thread featurecomprises a thread disposed internally within the proximal wedge.

Optionally, in any embodiment, the ramp assembly comprises a firstdistal ramp, a second distal ramp, a first proximal ramp, and a secondproximal ramp. Optionally, in any embodiment, the slideable couplingbetween at least one of the wedge assembly and the ramp assembly, theramp assembly and the upper endplate, assembly, and the ramp assemblyand the lower endplate assembly is at a transverse angle from thelongitudinal axis.

Optionally, in any embodiment, the transverse angle is about 0 degreesto about 90 degrees. Optionally, in any embodiment, the transverse angleis at least about 0 degrees. Optionally, in any embodiment, thetransverse angle is at most about 90 degrees. Optionally, in anyembodiment, the transverse angle is about 0 degrees to about 1 degrees,about 0 degrees to about 5 degrees, about 0 degrees to about 10 degrees,about 0 degrees to about 20 degrees, about 0 degrees to about 30degrees, about 0 degrees to about 40 degrees, about 0 degrees to about50 degrees, about 0 degrees to about 60 degrees, about 0 degrees toabout 70 degrees, about 0 degrees to about 80 degrees, about 0 degreesto about 90 degrees, about 1 degrees to about 5 degrees, about 1 degreesto about 10 degrees, about 1 degrees to about 20 degrees, about 1degrees to about 30 degrees, about 1 degrees to about 40 degrees, about1 degrees to about 50 degrees, about 1 degrees to about 60 degrees,about 1 degrees to about 70 degrees, about 1 degrees to about 80degrees, about 1 degrees to about 90 degrees, about 5 degrees to about10 degrees, about 5 degrees to about 20 degrees, about 5 degrees toabout 30 degrees, about 5 degrees to about 40 degrees, about 5 degreesto about 50 degrees, about 5 degrees to about 60 degrees, about 5degrees to about 70 degrees, about 5 degrees to about 80 degrees, about5 degrees to about 90 degrees, about 10 degrees to about 20 degrees,about 10 degrees to about 30 degrees, about 10 degrees to about 40degrees, about 10 degrees to about 50 degrees, about 10 degrees to about60 degrees, about 10 degrees to about 70 degrees, about 10 degrees toabout 80 degrees, about 10 degrees to about 90 degrees, about 20 degreesto about 30 degrees, about 20 degrees to about 40 degrees, about 20degrees to about 50 degrees, about 20 degrees to about 60 degrees, about20 degrees to about 70 degrees, about 20 degrees to about 80 degrees,about 20 degrees to about 90 degrees, about 30 degrees to about 40degrees, about 30 degrees to about 50 degrees, about 30 degrees to about60 degrees, about 30 degrees to about 70 degrees, about 30 degrees toabout 80 degrees, about 30 degrees to about 90 degrees, about 40 degreesto about 50 degrees, about 40 degrees to about 60 degrees, about 40degrees to about 70 degrees, about 40 degrees to about 80 degrees, about40 degrees to about 90 degrees, about 50 degrees to about 60 degrees,about 50 degrees to about 70 degrees, about 50 degrees to about 80degrees, about 50 degrees to about 90 degrees, about 60 degrees to about70 degrees, about 60 degrees to about 80 degrees, about 60 degrees toabout 90 degrees, about 70 degrees to about 80 degrees, about 70 degreesto about 90 degrees, or about 80 degrees to about 90 degrees.Optionally, in any embodiment, the transverse angle is about 0 degrees,about 1 degrees, about 5 degrees, about 10 degrees, about 20 degrees,about 30 degrees, about 40 degrees, about 50 degrees, about 60 degrees,about 70 degrees, about 80 degrees, or about 90 degrees.

Optionally, in any embodiment, the slideable coupling between at leastone of the wedge assembly and the ramp assembly, the ramp assembly andthe upper endplate, assembly, and the ramp assembly and the lowerendplate assembly comprises a protrusion and a slot. Optionally, in anyembodiment, the protrusion extends from at least one of the wedgeassembly, the ramp assembly, the upper endplate assembly, and the lowerendplate assembly, and wherein the slot is disposed in at least one ofthe upper endplate assembly, and the lower endplate assembly.Optionally, in any embodiment, the protrusion comprises a pin, a ridge,a dimple, a bolt, a screw, a bearing, or any combination thereof.Optionally, in any embodiment, the slot comprises a through slot, ablind slot, a t-slot, a v-slot, a groove, or any combination thereof.

Optionally, in any embodiment, the drive feature comprises a recessedregion configured to receive a driving instrument. Optionally, in anyembodiment, the recessed region comprises a slot, Phillips, pozidrive,frearson, robertson, 12-point flange, hex socket, security hex socket,star drive, security torx, ta, tri-point, tri-wing, spanner head,clutch, one-way, double-square, triple-square, polydrive, spline drive,double hex, bristol, a thread, a friction fit, or a pentalobe recess.Optionally, in any embodiment, the driving feature comprises aprotuberance extending therefrom and configured to be coupled to adriving instrument. Optionally, in any embodiment, the protuberancecomprises a hex, a hexalobular, a threaded, or a square protuberance.

Optionally, in any embodiment, the upper endplate assembly comprises afirst endplate and a second endplate, and wherein the lower endplateassembly comprises a third endplate and a fourth endplate. Optionally,in any embodiment, at least one of the first endplate and the secondendplate, the third endplate and the fourth endplate, the first proximalramp and the second proximal ramp, and the first distal ramp and thesecond distal ramp have mirrored equivalence. Optionally, in anyembodiment, at least one of the second endplate and the fourth endplateis larger than at least one of the first endplate and the thirdendplate. Optionally, in any embodiment, at least one of the exteriorfaces of the first end plate, the second endplate, the third endplate,and the fourth endplate comprise a texture configured to grip thevertebrae. Optionally, in any embodiment, the texturing comprises atooth, a ridge, a roughened area, a metallic coating, a ceramic coating,a keel, a spike, a projection, a groove, or any combination thereof.

Optionally, in any embodiment, at least one of the actuator, the wedgeassembly, the ramp assembly, the upper endplate assembly, and the lowerendplate assembly comprise titanium, cobalt, stainless steel, tantalum,platinum, PEEK, PEKK, carbon fiber, barium sulfate, hydroxyapatite, aceramic, zirconium oxide, silicon nitride, carbon, bone graft,demineralized bone matrix product, synthetic bone substitute, a bonemorphogenic agent, a bone growth inducing material, or any combinationthereof.

A second aspect provided herein is an expandable fusion system forimplantation between two adjacent vertebrae, the system comprising aninserter and an expandable fusion device comprising: an actuatorcomprising a drive feature and an longitudinal axis; a wedge assembly; aramp assembly; an upper endplate assembly; and a lower endplateassembly; wherein the device has a width comprising an external distancebetween at least one of the first endplate and the third endplate, andthe second endplate and the fourth endplate; wherein the device has aheight comprising an external distance between at least one of the firstendplate and the second endplate, and the third endplate and the fourthendplate; wherein actuation of the drive feature by a first number ofactuations in a first actuation direction increases the width withoutincreasing the height; and wherein actuation of the drive feature by asecond number of actuations beyond the first number of actuations in thefirst actuation direction increases at least one of the height and thewidth.

Optionally, in any embodiment, actuation of the drive feature by asecond number of actuations beyond the first number of actuations in thefirst actuation direction increases both the height and the width.Optionally, in any embodiment, actuation of the drive feature by asecond number of actuations beyond the first number of actuations in thefirst actuation direction increases the height without increasing thewidth.

Optionally, in any embodiment, the width of the device reaches an apexonce the drive feature is actuated by at least the first number ofactuations. Optionally, in any embodiment, the height of the devicereaches an apex once the drive feature is actuated by at least the firstand second number of actuations.

Optionally, in any embodiment, the first number of actuations is about0.5 actuations to about 10 actuations. Optionally, in any embodiment,the first number of actuations is at least about 0.5 actuations.Optionally, in any embodiment, the first number of actuations is at mostabout 10 actuations. Optionally, in any embodiment, the first number ofactuations is about 0.5 actuations to about 1 actuations, about 0.5actuations to about 1.5 actuations, about 0.5 actuations to about 2actuations, about 0.5 actuations to about 2.5 actuations, about 0.5actuations to about 3 actuations, about 0.5 actuations to about 3.5actuations, about 0.5 actuations to about 4 actuations, about 0.5actuations to about 5 actuations, about 0.5 actuations to about 6actuations, about 0.5 actuations to about 8 actuations, about 0.5actuations to about 10 actuations, about 1 actuations to about 1.5actuations, about 1 actuations to about 2 actuations, about 1 actuationsto about 2.5 actuations, about 1 actuations to about 3 actuations, about1 actuations to about 3.5 actuations, about 1 actuations to about 4actuations, about 1 actuations to about 5 actuations, about 1 actuationsto about 6 actuations, about 1 actuations to about 8 actuations, about 1actuations to about 10 actuations, about 1.5 actuations to about 2actuations, about 1.5 actuations to about 2.5 actuations, about 1.5actuations to about 3 actuations, about 1.5 actuations to about 3.5actuations, about 1.5 actuations to about 4 actuations, about 1.5actuations to about 5 actuations, about 1.5 actuations to about 6actuations, about 1.5 actuations to about 8 actuations, about 1.5actuations to about 10 actuations, about 2 actuations to about 2.5actuations, about 2 actuations to about 3 actuations, about 2 actuationsto about 3.5 actuations, about 2 actuations to about 4 actuations, about2 actuations to about 5 actuations, about 2 actuations to about 6actuations, about 2 actuations to about 8 actuations, about 2 actuationsto about 10 actuations, about 2.5 actuations to about 3 actuations,about 2.5 actuations to about 3.5 actuations, about 2.5 actuations toabout 4 actuations, about 2.5 actuations to about 5 actuations, about2.5 actuations to about 6 actuations, about 2.5 actuations to about 8actuations, about 2.5 actuations to about 10 actuations, about 3actuations to about 3.5 actuations, about 3 actuations to about 4actuations, about 3 actuations to about 5 actuations, about 3 actuationsto about 6 actuations, about 3 actuations to about 8 actuations, about 3actuations to about 10 actuations, about 3.5 actuations to about 4actuations, about 3.5 actuations to about 5 actuations, about 3.5actuations to about 6 actuations, about 3.5 actuations to about 8actuations, about 3.5 actuations to about 10 actuations, about 4actuations to about 5 actuations, about 4 actuations to about 6actuations, about 4 actuations to about 8 actuations, about 4 actuationsto about 10 actuations, about 5 actuations to about 6 actuations, about5 actuations to about 8 actuations, about 5 actuations to about 10actuations, about 6 actuations to about 8 actuations, about 6 actuationsto about 10 actuations, or about 8 actuations to about 10 actuations.Optionally, in any embodiment, the first number of actuations is about0.5 actuations, about 1 actuations, about 1.5 actuations, about 2actuations, about 2.5 actuations, about 3 actuations, about 3.5actuations, about 4 actuations, about 5 actuations, about 6 actuations,about 8 actuations, or about 10 actuations.

Optionally, in any embodiment, the second number of actuations is about0.5 actuations to about 10 actuations. Optionally, in any embodiment,the second number of actuations is at least about 0.5 actuations.Optionally, in any embodiment, the second number of actuations is atmost about 10 actuations. Optionally, in any embodiment, the secondnumber of actuations is about 0.5 actuations to about 1 actuations,about 0.5 actuations to about 1.5 actuations, about 0.5 actuations toabout 2 actuations, about 0.5 actuations to about 2.5 actuations, about0.5 actuations to about 3 actuations, about 0.5 actuations to about 3.5actuations, about 0.5 actuations to about 4 actuations, about 0.5actuations to about 5 actuations, about 0.5 actuations to about 6actuations, about 0.5 actuations to about 8 actuations, about 0.5actuations to about 10 actuations, about 1 actuations to about 1.5actuations, about 1 actuations to about 2 actuations, about 1 actuationsto about 2.5 actuations, about 1 actuations to about 3 actuations, about1 actuations to about 3.5 actuations, about 1 actuations to about 4actuations, about 1 actuations to about 5 actuations, about 1 actuationsto about 6 actuations, about 1 actuations to about 8 actuations, about 1actuations to about 10 actuations, about 1.5 actuations to about 2actuations, about 1.5 actuations to about 2.5 actuations, about 1.5actuations to about 3 actuations, about 1.5 actuations to about 3.5actuations, about 1.5 actuations to about 4 actuations, about 1.5actuations to about 5 actuations, about 1.5 actuations to about 6actuations, about 1.5 actuations to about 8 actuations, about 1.5actuations to about 10 actuations, about 2 actuations to about 2.5actuations, about 2 actuations to about 3 actuations, about 2 actuationsto about 3.5 actuations, about 2 actuations to about 4 actuations, about2 actuations to about 5 actuations, about 2 actuations to about 6actuations, about 2 actuations to about 8 actuations, about 2 actuationsto about 10 actuations, about 2.5 actuations to about 3 actuations,about 2.5 actuations to about 3.5 actuations, about 2.5 actuations toabout 4 actuations, about 2.5 actuations to about 5 actuations, about2.5 actuations to about 6 actuations, about 2.5 actuations to about 8actuations, about 2.5 actuations to about 10 actuations, about 3actuations to about 3.5 actuations, about 3 actuations to about 4actuations, about 3 actuations to about 5 actuations, about 3 actuationsto about 6 actuations, about 3 actuations to about 8 actuations, about 3actuations to about 10 actuations, about 3.5 actuations to about 4actuations, about 3.5 actuations to about 5 actuations, about 3.5actuations to about 6 actuations, about 3.5 actuations to about 8actuations, about 3.5 actuations to about 10 actuations, about 4actuations to about 5 actuations, about 4 actuations to about 6actuations, about 4 actuations to about 8 actuations, about 4 actuationsto about 10 actuations, about 5 actuations to about 6 actuations, about5 actuations to about 8 actuations, about 5 actuations to about 10actuations, about 6 actuations to about 8 actuations, about 6 actuationsto about 10 actuations, or about 8 actuations to about 10 actuations.Optionally, in any embodiment, the second number of actuations is about0.5 actuations, about 1 actuations, about 1.5 actuations, about 2actuations, about 2.5 actuations, about 3 actuations, about 3.5actuations, about 4 actuations, about 5 actuations, about 6 actuations,about 8 actuations, or about 10 actuations.

Optionally, in any embodiment, actuation of the drive feature in thefirst actuation direction by at least the first number of actuationsincreases the height of the device by about 30% to about 400%.Optionally, in any embodiment, actuation of the drive feature in thefirst actuation direction by at least the first number of actuationsincreases the height of the device by at least about 30%. Optionally, inany embodiment, actuation of the drive feature in the first actuationdirection by at least the first number of actuations increases theheight of the device by at most about 400%. Optionally, in anyembodiment, actuation of the drive feature in the first actuationdirection by at least the first number of actuations increases theheight of the device by about 30% to about 50%, about 30% to about 75%,about 30% to about 100%, about 30% to about 125%, about 30% to about150%, about 30% to about 175%, about 30% to about 200%, about 30% toabout 250%, about 30% to about 300%, about 30% to about 350%, about 30%to about 400%, about 50% to about 75%, about 50% to about 100%, about50% to about 125%, about 50% to about 150%, about 50% to about 175%,about 50% to about 200%, about 50% to about 250%, about 50% to about300%, about 50% to about 350%, about 50% to about 400%, about 75% toabout 100%, about 75% to about 125%, about 75% to about 150%, about 75%to about 175%, about 75% to about 200%, about 75% to about 250%, about75% to about 300%, about 75% to about 350%, about 75% to about 400%,about 100% to about 125%, about 100% to about 150%, about 100% to about175%, about 100% to about 200%, about 100% to about 250%, about 100% toabout 300%, about 100% to about 350%, about 100% to about 400%, about125% to about 150%, about 125% to about 175%, about 125% to about 200%,about 125% to about 250%, about 125% to about 300%, about 125% to about350%, about 125% to about 400%, about 150% to about 175%, about 150% toabout 200%, about 150% to about 250%, about 150% to about 300%, about150% to about 350%, about 150% to about 400%, about 175% to about 200%,about 175% to about 250%, about 175% to about 300%, about 175% to about350%, about 175% to about 400%, about 200% to about 250%, about 200% toabout 300%, about 200% to about 350%, about 200% to about 400%, about250% to about 300%, about 250% to about 350%, about 250% to about 400%,about 300% to about 350%, about 300% to about 400%, or about 350% toabout 400%. Optionally, in any embodiment, actuation of the drivefeature in the first actuation direction by at least the first number ofactuations increases the height of the device by about 30%, about 50%,about 75%, about 100%, about 125%, about 150%, about 175%, about 200%,about 250%, about 300%, about 350%, or about 400%.

Optionally, in any embodiment, actuation of the drive feature in thefirst actuation direction by at least the first and the second number ofactuations increases the width of the device by about 14% to about 150%.Optionally, in any embodiment, actuation of the drive feature in thefirst actuation direction by at least the first and the second number ofactuations increases the width of the device by at least about 14%.Optionally, in any embodiment, actuation of the drive feature in thefirst actuation direction by at least the first and the second number ofactuations increases the width of the device by at most about 150%.Optionally, in any embodiment, actuation of the drive feature in thefirst actuation direction by at least the first and the second number ofactuations increases the width of the device by about 14% to about 20%,about 14% to about 30%, about 14% to about 40%, about 14% to about 50%,about 14% to about 60%, about 14% to about 70%, about 14% to about 80%,about 14% to about 90%, about 14% to about 100%, about 14% to about120%, about 14% to about 150%, about 20% to about 30%, about 20% toabout 40%, about 20% to about 50%, about 20% to about 60%, about 20% toabout 70%, about 20% to about 80%, about 20% to about 90%, about 20% toabout 100%, about 20% to about 120%, about 20% to about 150%, about 30%to about 40%, about 30% to about 50%, about 30% to about 60%, about 30%to about 70%, about 30% to about 80%, about 30% to about 90%, about 30%to about 100%, about 30% to about 120%, about 30% to about 150%, about40% to about 50%, about 40% to about 60%, about 40% to about 70%, about40% to about 80%, about 40% to about 90%, about 40% to about 100%, about40% to about 120%, about 40% to about 150%, about 50% to about 60%,about 50% to about 70%, about 50% to about 80%, about 50% to about 90%,about 50% to about 100%, about 50% to about 120%, about 50% to about150%, about 60% to about 70%, about 60% to about 80%, about 60% to about90%, about 60% to about 100%, about 60% to about 120%, about 60% toabout 150%, about 70% to about 80%, about 70% to about 90%, about 70% toabout 100%, about 70% to about 120%, about 70% to about 150%, about 80%to about 90%, about 80% to about 100%, about 80% to about 120%, about80% to about 150%, about 90% to about 100%, about 90% to about 120%,about 90% to about 150%, about 100% to about 120%, about 100% to about150%, or about 120% to about 150%. Optionally, in any embodiment,actuation of the drive feature in the first actuation direction by atleast the first and the second number of actuations increases the widthof the device by about 14%, about 20%, about 30%, about 40%, about 50%,about 60%, about 70%, about 80%, about 90%, about 100%, about 120%, orabout 150%.

Optionally, in any embodiment, the actuator has a distal end and aproximal end. Optionally, in any embodiment, at least a portion of thedistal end comprises a first thread feature. Optionally, in anyembodiment, at least a portion of the proximal end comprises a secondthread feature, and wherein the proximal end comprises the drivefeature. Optionally, in any embodiment, at least one of the first threadfeature and the second thread feature comprise a thread disposedexternally around the actuator. Optionally, in any embodiment, the firstthread feature and the second thread feature have an opposite threadingdirection.

Optionally, in any embodiment, the wedge assembly comprises a distalwedge and a proximal wedge. Optionally, in any embodiment, actuation ofthe drive feature in the first direction converges the distal wedge andthe proximal wedge toward one another. Optionally, in any embodiment,the distal wedge comprises a third thread feature, and wherein the thirdthread feature is threadably coupled to the first thread feature.Optionally, in any embodiment, the proximal wedge comprises a fourththread feature, and wherein the fourth thread feature is threadablycoupled to the second thread feature. Optionally, in any embodiment, thethird thread feature comprises a thread disposed internally within thedistal wedge. Optionally, in any embodiment, the fourth thread featurecomprises a thread disposed internally within the proximal wedge.

Optionally, in any embodiment, the ramp assembly comprises a firstdistal ramp, a second distal ramp, a first proximal ramp, and a secondproximal ramp. Optionally, in any embodiment, the slideable couplingbetween at least one of the wedge assembly and the ramp assembly, theramp assembly and the upper endplate, assembly, and the ramp assemblyand the lower endplate assembly is at a transverse angle from thelongitudinal axis. Optionally, in any embodiment, the transverse angleis about 0 degrees to about 90 degrees. Optionally, in any embodiment,the slideable coupling between at least one of the wedge assembly andthe ramp assembly, the ramp assembly and the upper endplate, assembly,and the ramp assembly and the lower endplate assembly comprises aprotrusion and a slot. Optionally, in any embodiment, the protrusionextends from at least one of the wedge assembly, the ramp assembly, theupper endplate assembly, and the lower endplate assembly, and whereinthe slot is disposed in at least one of the upper endplate assembly, andthe lower endplate assembly. Optionally, in any embodiment, theprotrusion comprises a pin, a ridge, a dimple, a bolt, a screw, abearing, or any combination thereof. Optionally, in any embodiment, theslot comprises a through slot, a blind slot, a t-slot, a v-slot, agroove, or any combination thereof.

Optionally, in any embodiment, the drive feature comprises a recessedregion configured to receive a driving instrument. Optionally, in anyembodiment, the recessed region comprises a slot, Phillips, pozidrive,frearson, robertson, 12-point flange, hex socket, security hex socket,star drive, hexalobe, security torx, ta, tri-point, tri-wing, spannerhead, clutch, one-way, double-square, triple-square, polydrive, splinedrive, double hex, bristol, a thread, a friction fit, or a pentaloberecess or any other shaped recess. Optionally, in any embodiment, thedriving feature comprises a protuberance extending therefrom andconfigured to be coupled to a driving instrument. Optionally, in anyembodiment, the protuberance comprises a hex, a hexalobular, a threaded,or a square protuberance or any other shape protuberance.

Optionally, in any embodiment, the upper endplate assembly comprises afirst endplate and a second endplate, and wherein the lower endplateassembly comprises a third endplate and a fourth endplate. Optionally,in any embodiment, at least one of the first endplate and the secondendplate, the third endplate and the fourth endplate, the first proximalramp and the second proximal ramp, and the first distal ramp and thesecond distal ramp have mirrored equivalence. Optionally, in anyembodiment, at least one of the second endplate and the fourth endplateis larger than at least one of the first endplate and the thirdendplate. Optionally, in any embodiment, at least one of the exteriorfaces of the first end plate, the second endplate, the third endplate,and the fourth endplate comprise a texture configured to grip thevertebrae. Optionally, in any embodiment, the texturing comprises atooth, a ridge, a roughened area, a metallic coating, a ceramic coating,a keel, a spike, a projection, a groove, or any combination thereof.

Optionally, in any embodiment, at least one of the actuator, the wedgeassembly, the upper endplate assembly, and the lower endplate assemblycomprise titanium, cobalt, stainless steel, tantalum, platinum, PEEK,PEKK, PEI, PET, carbon fiber, barium sulfate, hydroxyapatite, a ceramic,zirconium oxide, silicon nitride, carbon, bone graft, demineralized bonematrix product, synthetic bone substitute, a bone morphogenic agent, abone growth inducing material, or any combination thereof.

A third aspect provided herein is a method for implanting an expandablefusion device between two adjacent vertebrae comprising: inserting thedevice, having a width and a height, between two adjacent vertebrae;actuating a drive feature by a first number of actuations in a firstactuation to increase the width without increasing the height; andactuating the drive feature by the second number of actuations beyondthe first number of actuations in the first actuation direction toincrease at least one of the height and the width; attaching an inserterto the expandable fusion device, the device having a width and a heightand comprising a drive feature.

Optionally, in any embodiment, actuation of the drive feature by asecond number of actuations beyond the first number of actuations in thefirst actuation direction increases both the height and the width.Optionally, in any embodiment, actuation of the drive feature by asecond number of actuations beyond the first number of actuations in thefirst actuation direction increases the height without increasing thewidth.

Optionally, in any embodiment, the width of the device reaches an apexonce the drive feature is actuated by at least the first number ofactuations. Optionally, in any embodiment, the height of the devicereaches an apex once the drive feature is actuated by at least the firstand second number of actuations.

Optionally, in any embodiment, the first number of actuations is about0.5 actuations to about 10 actuations. Optionally, in any embodiment,the first number of actuations is at least about 0.5 actuations.Optionally, in any embodiment, the first number of actuations is at mostabout 10 actuations. Optionally, in any embodiment, the first number ofactuations is about 0.5 actuations to about 1 actuations, about 0.5actuations to about 1.5 actuations, about 0.5 actuations to about 2actuations, about 0.5 actuations to about 2.5 actuations, about 0.5actuations to about 3 actuations, about 0.5 actuations to about 3.5actuations, about 0.5 actuations to about 4 actuations, about 0.5actuations to about 5 actuations, about 0.5 actuations to about 6actuations, about 0.5 actuations to about 8 actuations, about 0.5actuations to about 10 actuations, about 1 actuations to about 1.5actuations, about 1 actuations to about 2 actuations, about 1 actuationsto about 2.5 actuations, about 1 actuations to about 3 actuations, about1 actuations to about 3.5 actuations, about 1 actuations to about 4actuations, about 1 actuations to about 5 actuations, about 1 actuationsto about 6 actuations, about 1 actuations to about 8 actuations, about 1actuations to about 10 actuations, about 1.5 actuations to about 2actuations, about 1.5 actuations to about 2.5 actuations, about 1.5actuations to about 3 actuations, about 1.5 actuations to about 3.5actuations, about 1.5 actuations to about 4 actuations, about 1.5actuations to about 5 actuations, about 1.5 actuations to about 6actuations, about 1.5 actuations to about 8 actuations, about 1.5actuations to about 10 actuations, about 2 actuations to about 2.5actuations, about 2 actuations to about 3 actuations, about 2 actuationsto about 3.5 actuations, about 2 actuations to about 4 actuations, about2 actuations to about 5 actuations, about 2 actuations to about 6actuations, about 2 actuations to about 8 actuations, about 2 actuationsto about 10 actuations, about 2.5 actuations to about 3 actuations,about 2.5 actuations to about 3.5 actuations, about 2.5 actuations toabout 4 actuations, about 2.5 actuations to about 5 actuations, about2.5 actuations to about 6 actuations, about 2.5 actuations to about 8actuations, about 2.5 actuations to about 10 actuations, about 3actuations to about 3.5 actuations, about 3 actuations to about 4actuations, about 3 actuations to about 5 actuations, about 3 actuationsto about 6 actuations, about 3 actuations to about 8 actuations, about 3actuations to about 10 actuations, about 3.5 actuations to about 4actuations, about 3.5 actuations to about 5 actuations, about 3.5actuations to about 6 actuations, about 3.5 actuations to about 8actuations, about 3.5 actuations to about 10 actuations, about 4actuations to about 5 actuations, about 4 actuations to about 6actuations, about 4 actuations to about 8 actuations, about 4 actuationsto about 10 actuations, about 5 actuations to about 6 actuations, about5 actuations to about 8 actuations, about 5 actuations to about 10actuations, about 6 actuations to about 8 actuations, about 6 actuationsto about 10 actuations, or about 8 actuations to about 10 actuations.Optionally, in any embodiment, the first number of actuations is about0.5 actuations, about 1 actuations, about 1.5 actuations, about 2actuations, about 2.5 actuations, about 3 actuations, about 3.5actuations, about 4 actuations, about 5 actuations, about 6 actuations,about 8 actuations, or about 10 actuations.

Optionally, in any embodiment, the second number of actuations is about0.5 actuations to about 10 actuations. Optionally, in any embodiment,the second number of actuations is at least about 0.5 actuations.Optionally, in any embodiment, the second number of actuations is atmost about 10 actuations. Optionally, in any embodiment, the secondnumber of actuations is about 0.5 actuations to about 1 actuations,about 0.5 actuations to about 1.5 actuations, about 0.5 actuations toabout 2 actuations, about 0.5 actuations to about 2.5 actuations, about0.5 actuations to about 3 actuations, about 0.5 actuations to about 3.5actuations, about 0.5 actuations to about 4 actuations, about 0.5actuations to about 5 actuations, about 0.5 actuations to about 6actuations, about 0.5 actuations to about 8 actuations, about 0.5actuations to about 10 actuations, about 1 actuations to about 1.5actuations, about 1 actuations to about 2 actuations, about 1 actuationsto about 2.5 actuations, about 1 actuations to about 3 actuations, about1 actuations to about 3.5 actuations, about 1 actuations to about 4actuations, about 1 actuations to about 5 actuations, about 1 actuationsto about 6 actuations, about 1 actuations to about 8 actuations, about 1actuations to about 10 actuations, about 1.5 actuations to about 2actuations, about 1.5 actuations to about 2.5 actuations, about 1.5actuations to about 3 actuations, about 1.5 actuations to about 3.5actuations, about 1.5 actuations to about 4 actuations, about 1.5actuations to about 5 actuations, about 1.5 actuations to about 6actuations, about 1.5 actuations to about 8 actuations, about 1.5actuations to about 10 actuations, about 2 actuations to about 2.5actuations, about 2 actuations to about 3 actuations, about 2 actuationsto about 3.5 actuations, about 2 actuations to about 4 actuations, about2 actuations to about 5 actuations, about 2 actuations to about 6actuations, about 2 actuations to about 8 actuations, about 2 actuationsto about 10 actuations, about 2.5 actuations to about 3 actuations,about 2.5 actuations to about 3.5 actuations, about 2.5 actuations toabout 4 actuations, about 2.5 actuations to about 5 actuations, about2.5 actuations to about 6 actuations, about 2.5 actuations to about 8actuations, about 2.5 actuations to about 10 actuations, about 3actuations to about 3.5 actuations, about 3 actuations to about 4actuations, about 3 actuations to about 5 actuations, about 3 actuationsto about 6 actuations, about 3 actuations to about 8 actuations, about 3actuations to about 10 actuations, about 3.5 actuations to about 4actuations, about 3.5 actuations to about 5 actuations, about 3.5actuations to about 6 actuations, about 3.5 actuations to about 8actuations, about 3.5 actuations to about 10 actuations, about 4actuations to about 5 actuations, about 4 actuations to about 6actuations, about 4 actuations to about 8 actuations, about 4 actuationsto about 10 actuations, about 5 actuations to about 6 actuations, about5 actuations to about 8 actuations, about 5 actuations to about 10actuations, about 6 actuations to about 8 actuations, about 6 actuationsto about 10 actuations, or about 8 actuations to about 10 actuations.Optionally, in any embodiment, the second number of actuations is about0.5 actuations, about 1 actuations, about 1.5 actuations, about 2actuations, about 2.5 actuations, about 3 actuations, about 3.5actuations, about 4 actuations, about 5 actuations, about 6 actuations,about 8 actuations, or about 10 actuations.

Optionally, in any embodiment, actuation of the drive feature in thefirst actuation direction by at least the first number of actuationsincreases the height of the device by about 30% to about 400%.Optionally, in any embodiment, actuation of the drive feature in thefirst actuation direction by at least the first number of actuationsincreases the height of the device by at least about 30%. Optionally, inany embodiment, actuation of the drive feature in the first actuationdirection by at least the first number of actuations increases theheight of the device by at most about 400%. Optionally, in anyembodiment, actuation of the drive feature in the first actuationdirection by at least the first number of actuations increases theheight of the device by about 30% to about 50%, about 30% to about 75%,about 30% to about 100%, about 30% to about 125%, about 30% to about150%, about 30% to about 175%, about 30% to about 200%, about 30% toabout 250%, about 30% to about 300%, about 30% to about 350%, about 30%to about 400%, about 50% to about 75%, about 50% to about 100%, about50% to about 125%, about 50% to about 150%, about 50% to about 175%,about 50% to about 200%, about 50% to about 250%, about 50% to about300%, about 50% to about 350%, about 50% to about 400%, about 75% toabout 100%, about 75% to about 125%, about 75% to about 150%, about 75%to about 175%, about 75% to about 200%, about 75% to about 250%, about75% to about 300%, about 75% to about 350%, about 75% to about 400%,about 100% to about 125%, about 100% to about 150%, about 100% to about175%, about 100% to about 200%, about 100% to about 250%, about 100% toabout 300%, about 100% to about 350%, about 100% to about 400%, about125% to about 150%, about 125% to about 175%, about 125% to about 200%,about 125% to about 250%, about 125% to about 300%, about 125% to about350%, about 125% to about 400%, about 150% to about 175%, about 150% toabout 200%, about 150% to about 250%, about 150% to about 300%, about150% to about 350%, about 150% to about 400%, about 175% to about 200%,about 175% to about 250%, about 175% to about 300%, about 175% to about350%, about 175% to about 400%, about 200% to about 250%, about 200% toabout 300%, about 200% to about 350%, about 200% to about 400%, about250% to about 300%, about 250% to about 350%, about 250% to about 400%,about 300% to about 350%, about 300% to about 400%, or about 350% toabout 400%. Optionally, in any embodiment, actuation of the drivefeature in the first actuation direction by at least the first number ofactuations increases the height of the device by about 30%, about 50%,about 75%, about 100%, about 125%, about 150%, about 175%, about 200%,about 250%, about 300%, about 350%, or about 400%.

Optionally, in any embodiment, actuation of the drive feature in thefirst actuation direction by at least the first and the second number ofactuations increases the width of the device by about 14% to about 150%.Optionally, in any embodiment, actuation of the drive feature in thefirst actuation direction by at least the first and the second number ofactuations increases the width of the device by at least about 14%.Optionally, in any embodiment, actuation of the drive feature in thefirst actuation direction by at least the first and the second number ofactuations increases the width of the device by at most about 150%.Optionally, in any embodiment, actuation of the drive feature in thefirst actuation direction by at least the first and the second number ofactuations increases the width of the device by about 14% to about 20%,about 14% to about 30%, about 14% to about 40%, about 14% to about 50%,about 14% to about 60%, about 14% to about 70%, about 14% to about 80%,about 14% to about 100%, about 14% to about 120%, about 14% to about140%, about 14% to about 150%, about 20% to about 30%, about 20% toabout 40%, about 20% to about 50%, about 20% to about 60%, about 20% toabout 70%, about 20% to about 80%, about 20% to about 100%, about 20% toabout 120%, about 20% to about 140%, about 20% to about 150%, about 30%to about 40%, about 30% to about 50%, about 30% to about 60%, about 30%to about 70%, about 30% to about 80%, about 30% to about 100%, about 30%to about 120%, about 30% to about 140%, about 30% to about 150%, about40% to about 50%, about 40% to about 60%, about 40% to about 70%, about40% to about 80%, about 40% to about 100%, about 40% to about 120%,about 40% to about 140%, about 40% to about 150%, about 50% to about60%, about 50% to about 70%, about 50% to about 80%, about 50% to about100%, about 50% to about 120%, about 50% to about 140%, about 50% toabout 150%, about 60% to about 70%, about 60% to about 80%, about 60% toabout 100%, about 60% to about 120%, about 60% to about 140%, about 60%to about 150%, about 70% to about 80%, about 70% to about 100%, about70% to about 120%, about 70% to about 140%, about 70% to about 150%,about 80% to about 100%, about 80% to about 120%, about 80% to about140%, about 80% to about 150%, about 100% to about 120%, about 100% toabout 140%, about 100% to about 150%, about 120% to about 140%, about120% to about 150%, or about 140% to about 150%. Optionally, in anyembodiment, actuation of the drive feature in the first actuationdirection by at least the first and the second number of actuationsincreases the width of the device by about 14%, about 20%, about 30%,about 40%, about 50%, about 60%, about 70%, about 80%, about 100%, about120%, about 140%, or about 150%.

Optionally, in any embodiment, the actuator has a distal end and aproximal end. Optionally, in any embodiment, at least a portion of thedistal end comprises a first thread feature. Optionally, in anyembodiment, at least a portion of the proximal end comprises a secondthread feature, and wherein the proximal end comprises the drivefeature. Optionally, in any embodiment, at least one of the first threadfeature and the second thread feature comprise a thread disposedexternally around the actuator. Optionally, in any embodiment, the firstthread feature and the second thread feature have an opposite threadingdirection.

Optionally, in any embodiment, the wedge assembly comprises a distalwedge and a proximal wedge. Optionally, in any embodiment, actuation ofthe drive feature in the first direction converges the distal wedge andthe proximal wedge toward one another. Optionally, in any embodiment,the distal wedge comprises a third thread feature, and wherein the thirdthread feature is threadably coupled to the first thread feature.Optionally, in any embodiment, the proximal wedge comprises a fourththread feature, and wherein the fourth thread feature is threadablycoupled to the second thread feature. Optionally, in any embodiment, thethird thread feature comprises a thread disposed internally within thedistal wedge. Optionally, in any embodiment, the fourth thread featurecomprises a thread disposed internally within the proximal wedge.

Optionally, in any embodiment, the ramp assembly comprises a firstdistal ramp, a second distal ramp, a first proximal ramp, and a secondproximal ramp. Optionally, in any embodiment, the slideable couplingbetween at least one of the wedge assembly and the ramp assembly, theramp assembly and the upper endplate, assembly, and the ramp assemblyand the lower endplate assembly is at a transverse angle from thelongitudinal axis. Optionally, in any embodiment, the transverse angleis about 30 degrees to about 90 degrees. Optionally, in any embodiment,the slideable coupling between at least one of the wedge assembly andthe ramp assembly, the ramp assembly and the upper endplate, assembly,and the ramp assembly and the lower endplate assembly comprises aprotrusion and a slot. Optionally, in any embodiment, the protrusionextends from at least one of the wedge assembly, the ramp assembly, theupper endplate assembly, and the lower endplate assembly, and whereinthe slot is disposed in at least one of the upper endplate assembly, andthe lower endplate assembly. Optionally, in any embodiment, theprotrusion comprises a pin, a ridge, a dimple, a bolt, a screw, abearing, or any combination thereof. Optionally, in any embodiment, theslot comprises a through slot, a blind slot, a t-slot, a v-slot, agroove, or any combination thereof.

Optionally, in any embodiment, the drive feature comprises a recessedregion configured to receive a driving instrument. Optionally, in anyembodiment, the recessed region comprises a slot, Phillips, pozidrive,frearson, robertson, 12-point flange, hex socket, security hex socket,star drive, security torx, ta, tri-point, tri-wing, spanner head,clutch, one-way, double-square, triple-square, polydrive, spline drive,double hex, bristol, a thread, a friction fit, or a pentalobe recess.Optionally, in any embodiment, the driving feature comprises aprotuberance extending therefrom and configured to be coupled to adriving instrument. Optionally, in any embodiment, the protuberancecomprises a hex, a hexalobular, a threaded a square protuberance.

Optionally, in any embodiment, the upper endplate assembly comprises afirst endplate and a second endplate, and wherein the lower endplateassembly comprises a third endplate and a fourth endplate. Optionally,in any embodiment, at least one of the first endplate and the secondendplate, the third endplate and the fourth endplate, the first proximalramp and the second proximal ramp, and the first distal ramp and thesecond distal ramp have mirrored equivalence. Optionally, in anyembodiment, at least one of the second endplate and the fourth endplateis larger than at least one of the first endplate and the thirdendplate. Optionally, in any embodiment, at least one of the exteriorfaces of the first end plate, the second endplate, the third endplate,and the fourth endplate comprise a texture configured to grip thevertebrae. Optionally, in any embodiment, the texturing comprises atooth, a ridge, a roughened area, a metallic coating, a ceramic coating,a keel, a spike, a projection, a groove, or any combination thereof.

Optionally, in any embodiment, at least one of the actuator, the wedgeassembly, the upper endplate assembly, and the lower endplate assemblycomprise titanium, cobalt, stainless steel, tantalum, platinum, PEEK,PEKK, carbon fiber, barium sulfate, hydroxyapatite, a ceramic, zirconiumoxide, silicon nitride, carbon, bone graft, demineralized bone matrixproduct, synthetic bone substitute, a bone morphogenic agent, a bonegrowth inducing material, or any combination thereof.

Further areas of applicability of the present disclosure will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating the preferred or exemplary embodiments of the disclosure, areintended for purposes of illustration only and are not intended to limitthe scope of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the disclosure are set forth with particularity inthe appended claims. A better understanding of the features andadvantages of the present disclosure will be obtained by reference tothe following detailed description that sets forth illustrativeembodiments, in which the principles of the disclosure are utilized, andthe accompanying drawings of which:

FIG. 1 depicts an exemplary first expandable fusion device implantedbetween two vertebral bodies in initial collapsed state.

FIG. 2 depicts an exemplary first expandable fusion device implantedbetween two vertebral bodies in fully expanded state.

FIG. 3 depicts a perspective view of an exemplary first expandablefusion device in its initial collapsed state.

FIG. 4 depicts a perspective view of an exemplary first expandablefusion device in its fully expanded state.

FIG. 5 depicts an exploded view of an exemplary first expandable fusiondevice.

FIG. 6A depicts a planar top view of an exemplary first expandablefusion device in initial collapsed state.

FIG. 6B depicts a planar end view of an exemplary first expandablefusion device in initial collapsed state.

FIG. 6C depicts a planar top view of an exemplary first expandablefusion device fully expanded in width.

FIG. 6D depicts a planar end view of an exemplary first expandablefusion device fully expanded in width.

FIG. 6E depicts a planar top view of an exemplary first expandablefusion device fully expanded in both width and height.

FIG. 6F depicts a planar end view of an exemplary first expandablefusion device fully expanded in both width and height.

FIG. 7A depicts a detailed view of an exemplary first expandable fusiondevice in its initial collapsed state and illustrates the articulationresponsible for delay in height expansion.

FIG. 7B depicts a detailed view of an exemplary first expandable fusiondevice in a partially width expanded state.

FIG. 7C depicts a detailed view of an exemplary first expandable fusiondevice in a partially width and height expanded state.

FIG. 8A depicts a bottom view of an exemplary endplate.

FIG. 8B depicts a top view of an exemplary endplate.

FIG. 9A depicts an exemplary endplate with T-shaped slots.

FIG. 9B depicts an exemplary endplate with L-shaped slots.

FIG. 9C depicts an exemplary endplate with Y-shaped slots.

FIG. 9D depicts an exemplary endplate with F-shaped slots.

FIG. 9E depicts an exemplary endplate with rectilinear slots.

FIG. 10A depicts a perspective top view of an exemplary endplate.

FIG. 10B depicts a bottom view of an exemplary endplate.

FIG. 10C depicts a perspective view of an exemplary first expandablefusion device in fully expanded state.

FIG. 10D1 depicts a perspective view of an exemplary first expandablefusion device in initial collapsed state.

FIG. 10D2 depicts a perspective view of an exemplary first expandablefusion device in fully expanded state.

FIG. 10D3 depicts a perspective view of an exemplary first expandablefusion device in fully expanded state and assembled with bone fasteners.

FIG. 11A depicts end view of an exemplary first expandable fusion devicewith all planar endplates.

FIG. 11B depicts end view of an exemplary first expandable fusion devicewith all convex endplates.

FIG. 11C depicts end view of an exemplary first expandable fusion devicewith all individually convex endplates.

FIG. 11D depicts end view of an exemplary first expandable fusion devicewith all planar endplates, with some of the endplates having differentheights.

FIG. 11E depicts end view of an exemplary first expandable fusion devicewith the top and bottom plates generally convex and lordotic.

FIG. 11F depicts end view of an exemplary first expandable fusion devicewith all convex endplates, with some of the endplates having differentheights.

FIG. 11G depicts end view of an exemplary first expandable fusion devicewith flat and lordotic endplates.

FIG. 11H depicts end view of an exemplary first expandable fusion devicewith flat bottom endplates, individually convex top endplates havingdifferent lengths.

FIG. 11I depicts end view of an exemplary first expandable fusion devicewith two generally convex top endplates and two flat bottom endplates.

FIG. 12A depicts side view of an exemplary first expandable fusiondevice with all planar endplates.

FIG. 12B depicts side view of an exemplary first expandable fusiondevice with all domed endplates.

FIG. 12C depicts side view of an exemplary first expandable fusiondevice with all planar and ramped endplates.

FIG. 12D depicts end view of an exemplary first expandable fusion devicewith all planar and domed endplates.

FIG. 13A depicts top view of an exemplary first expandable fusion devicewith all endplates of same length in initial collapsed state.

FIG. 13B depicts top view of an exemplary first expandable fusion devicewith endplates of different lengths in initial collapsed state.

FIG. 13C depicts top view of an exemplary first expandable fusion devicewith all endplates of same length in fully width expanded state.

FIG. 13D depicts top view of an exemplary first expandable fusion devicewith endplates of different lengths in fully width expanded state.

FIG. 14A depicts side views of the height expansion of an exemplaryfirst expandable fusion device.

FIG. 14B1 depicts a top view of the collapsed state of an exemplaryfirst expandable fusion device configured to expand unevenly on bothends.

FIG. 14B2 depicts a top view of a fully expanded state of an exemplaryfirst expandable fusion device with an alternative expansion mechanismand designed to expand unevenly on both ends.

FIG. 15A depicts side views of the width expansion of an exemplary firstexpandable fusion device.

FIG. 15B depicts a top view of an initial collapsed state of anexemplary first expandable fusion device with different length endplatesdesigned to achieve more width expansion on one side than on the other.

FIG. 15C depicts a top view of a fully width expanded state of anexemplary first expandable fusion device with different length endplatesdesigned to achieve more width expansion on one side than on the other.

FIG. 15D depicts a perspective view of a fully expanded state of anexemplary first expandable fusion device with different length endplatesdesigned to achieve more width expansion on one side than on the other.

FIG. 15E depicts a perspective view of an exemplary distal wedge withuneven ramps.

FIG. 15F depicts a perspective view of an exemplary proximal wedge withuneven ramps.

FIG. 15G depicts a perspective view of an exemplary ramp.

FIG. 16 depicts end views of the height expansion of an exemplary firstexpandable fusion device.

FIG. 17A depicts an inside perspective view of an exemplary ramp.

FIG. 17B depicts an outside perspective view of an exemplary ramp.

FIG. 18A depicts an inside perspective view of an exemplary ramp withL-shaped branches.

FIG. 18B depicts an inside perspective view of an exemplary ramp withC-shaped branches.

FIG. 18C depicts an inside perspective view of an exemplary ramp withT-shaped branches and T-shaped channel.

FIG. 18D depicts an inside perspective view of an exemplary ramp withY-shaped branches and Y-shaped channel.

FIG. 18E depicts an inside perspective view of an exemplary ramp with aninside T-shaped branches and Y-shaped channel.

FIG. 19A depicts an inside perspective view of an exemplary ramp withcylindrical branches of rectilinear cross-section.

FIG. 19B depicts an outside perspective view of an exemplary ramp withcylindrical branches of rectilinear cross-section.

FIG. 19C depicts an inside perspective view of an exemplary ramp withcylindrical branches of L-shaped cross-section.

FIG. 19D depicts an outside perspective view of an exemplary ramp withcylindrical branches of L-shaped cross-section.

FIG. 19E depicts an inside perspective view of an exemplary ramp withcylindrical branches of T-shaped cross-section.

FIG. 19F depicts an outside perspective view of an exemplary ramp withcylindrical branches of T-shaped cross-section.

FIG. 19G1 depicts a detailed section view of articulation between anexemplary ramp and of an exemplary endplate in unassembled state.

FIG. 19G2 depicts a detailed section view of articulation an exemplaryramp and an exemplary endplate in a partially assembled state.

FIG. 19G3 depicts a detailed section view of articulation between anexemplary ramp and of an exemplary endplate in a fully assembled state,in which the travel range of a ramp is limited.

FIG. 19H1 depicts detailed view of articulation between an exemplaryramp, an exemplary endplate, and an exemplary fastener in which thetravel range of a ramp is limited.

FIG. 19H2 depicts detailed exploded view of articulation between anexemplary ramp, an exemplary endplate, and an exemplary fastener inwhich the travel range of a ramp is limited.

FIG. 20 depicts a perspective view of an embodiment of an exemplaryactuator.

FIG. 21A depicts a perspective view of an exemplary actuator.

FIG. 21B depicts a perspective view of an exemplary actuator.

FIG. 22 depicts a perspective view of an exemplary retaining pin.

FIG. 23 depicts a perspective view of an exemplary retaining set screw.

FIG. 24 depicts a perspective view of an exemplary retaining c-clip.

FIG. 25 depicts a section view of articulation between an exemplaryproximal wedge, an exemplary actuator, and an exemplary retainingc-clip.

FIG. 26A depicts a rear perspective view of an exemplary proximal wedge.

FIG. 26B depicts a front perspective view of an exemplary proximalwedge.

FIG. 27A depicts a perspective view of an exemplary proximal wedge withT-shaped projections.

FIG. 27B depicts a perspective view of an exemplary proximal wedge withthreaded central aperture and alternative instrument attachmentfeatures.

FIG. 27C depicts a perspective view of an exemplary proximal wedge withT-shaped projections and alternative instrument attachment features.

FIG. 27D depicts a perspective view of an exemplary proximal wedge withT-shaped projections, alternative instrument attachment features and analternative side aperture shape.

FIG. 28A depicts a front perspective view of an exemplary distal wedge.

FIG. 28B depicts a rear perspective view of an exemplary distal wedge.

FIG. 29A depicts a front perspective view of an exemplary distal wedgewith T-shaped projections.

FIG. 29B depicts a front perspective view of an exemplary distal wedgewith T-shaped projections and without side apertures.

FIG. 30 depicts a perspective view of an exemplary inserter instrument.

FIG. 31 depicts a perspective view of an exemplary inserter instrument.

FIG. 32 depicts a detailed perspective view of the distal end of anexemplary inserter instrument.

FIG. 33 depicts a perspective view of an exemplary expansion driverinstrument.

FIG. 34 depicts a perspective view of an exemplary first expandablefusion device attached to an exemplary inserter instrument.

FIG. 35 depicts an exemplary first expandable fusion device implantedbetween two vertebral bodies in an initial collapsed state while havingan exemplary inserter instrument attached to it.

FIG. 36 depicts a perspective view of an exemplary first expandablefusion device attached to an exemplary inserter instrument with anexemplary expansion driver instrument.

FIG. 37 depicts a detailed perspective view of an exemplary firstexpandable fusion device attached to an exemplary inserter instrument.

FIG. 38 depicts a detailed perspective view of an exemplary firstexpandable fusion device in a partially width expanded state attached toan exemplary inserter instrument.

FIG. 39 depicts a detailed perspective view of an exemplary firstexpandable fusion device in a fully width expanded state attached to anexemplary inserter instrument.

FIG. 40 depicts a detailed perspective view of an exemplary firstexpandable fusion device in a fully width and height expanded stateattached to an exemplary inserter instrument.

FIG. 41 depicts a perspective view of an exemplary first expandablefusion device in a fully width and height expanded state filled withgraft material and attached to an exemplary inserter instrument.

FIG. 42 depicts an exemplary first expandable fusion device implantedbetween two vertebral bodies in a fully expanded state and filled withgraft material.

FIG. 43 depicts an exemplary inserter instrument.

FIG. 44 depicts a detailed section view of an exemplary actuationmechanism of an exemplary inserter instrument.

FIG. 45 depicts a detailed view of the distal end of the main shaft ofan exemplary inserter instrument.

FIG. 46 depicts a detailed view of the distal end of an exemplaryinserter instrument.

FIG. 47 depicts a detailed section view of the articulation between anexemplary first expandable fusion device and an exemplary inserterinstrument.

FIG. 48 depicts a detailed perspective view of an exemplary firstexpandable fusion device in an initial collapsed state attached to anexemplary inserter instrument in an unlocked state.

FIG. 49 depicts a detailed perspective view of an exemplary firstexpandable fusion device in an initial collapsed state attached to anexemplary inserter instrument in a locked state.

FIG. 50 depicts a perspective view of an exemplary first expandablefusion device attached to an exemplary inserter instrument with anexemplary expansion driver instrument.

FIG. 51 depicts a perspective view of an exemplary first expandablefusion device in a fully width expanded state attached to an exemplaryinserter instrument.

FIG. 52 depicts a perspective view of an exemplary first expandablefusion device in a fully width and height expanded state and attached toan exemplary inserter instrument.

FIG. 53 depicts a perspective view of an exemplary first expandablefusion device in a fully width and height expanded state filled withgraft material and attached to an exemplary inserter instrument.

FIG. 54A depicts a perspective view of an exemplary second expandablefusion device in an initial collapsed state.

FIG. 54B depicts a perspective view of an exemplary second expandablefusion device of FIG. 54A in a fully expanded state.

FIG. 54C depicts an exploded view of an exemplary second expandablefusion device.

FIG. 55A depicts a front view of an exemplary proximal wedge, used in anexemplary second expandable fusion device of FIGS. 54A-54C.

FIG. 55B depicts a rear view of an exemplary proximal wedge, used in anexemplary second expandable fusion device of FIGS. 54A-54C.

FIG. 56A depicts a perspective view of an exemplary third expandablefusion device in an initial collapsed state.

FIG. 56B depicts a perspective view of an exemplary third expandablefusion in a fully expanded state.

FIG. 56C depicts an exploded view of an exemplary third expandablefusion device.

FIG. 57A depicts a right view of an exemplary ramp of an exemplary thirdexpandable fusion device.

FIG. 57B depicts a left view of an exemplary ramp of an exemplary thirdexpandable fusion device.

FIG. 58 depicts a bottom view of an exemplary endplate of an exemplarythird expandable fusion device.

FIG. 59A depicts a perspective view of an exemplary fourth expandablefusion device in an initial collapsed state.

FIG. 59B depicts a perspective view of an exemplary fourth expandablefusion device of FIG. 59A in a fully expanded state.

FIG. 59C depicts a top view of an exemplary fourth expandable fusiondevice of FIG. 59A in an initial fully collapsed state.

FIG. 59D depicts a perspective view of partial assembly of an exemplaryfourth expandable fusion device comprising two opposing endplates.

FIG. 60A depicts a perspective view of an exemplary fifth expandablefusion device in a fully expanded state.

FIG. 60B depicts a side view of an exemplary fifth expandable fusiondevice of FIG. 60A in a fully expanded state.

FIG. 61A depicts a perspective view of an exemplary sixth expandablefusion device in a fully expanded state.

FIG. 61B depicts an exploded view of an exemplary sixth expandablefusion device.

FIG. 62A depicts a perspective view of an exemplary seventh expandablefusion device in a fully expanded state.

FIG. 62B depicts an exploded view of an exemplary seventh expandablefusion device.

FIG. 63A depicts a perspective view of an exemplary eighth expandablefusion device in an initial collapsed state.

FIG. 63B depicts a perspective view of an exemplary eighth expandablefusion device in a fully width expanded state.

FIG. 63C depicts a perspective view of an exemplary eighth expandablefusion device in a fully expanded state.

FIG. 63D depicts an exploded view of an exemplary eighth expandablefusion.

FIG. 64 depicts a perspective view of an exemplary eighth proximalwedge, used in an exemplary expandable fusion device.

FIG. 65A depicts a perspective view of an exemplary ninth expandablefusion device in an initial collapsed state.

FIG. 65B depicts a perspective view of an exemplary ninth expandablefusion device in a fully expanded state.

FIG. 65C depicts a partially assembled perspective view of an exemplaryninth expandable fusion device in an initial collapsed state.

FIG. 65D depicts a partially assembled perspective view of an exemplaryninth expandable fusion device in a partially width expanded state(linear width expansion only).

FIG. 65E depicts a partially assembled perspective view of an exemplaryninth expandable fusion device in a fully width expanded state (bothlinear and angular expansion completed).

FIG. 66A depicts a perspective view of an exemplary tenth expandablefusion device in a fully expanded state.

FIG. 66B depicts a perspective view of an exemplary tenth expandablefusion device in an initial collapsed state.

FIG. 66C depicts a perspective view of an exemplary tenth expandablefusion device in a fully width expanded state.

FIG. 66D depicts a top perspective view of an exemplary tenth compoundendplate, used in an exemplary expandable fusion device.

FIG. 67A depicts a perspective view of an exemplary eleventh expandablefusion device in a fully expanded state.

FIG. 67B depicts a perspective view of an exemplary eleventh endplatecomplex, used in an exemplary expandable fusion device.

FIG. 67C depicts a perspective view of an exemplary eleventh expandablefusion device of FIG. 67A in an initial collapsed state.

FIG. 67D depicts a perspective view of an exemplary eleventh expandablefusion device of FIG. 67A in a fully width expanded state.

FIG. 68 depicts a perspective view of an exemplary twelfth expandablefusion device in an initial collapsed state.

FIG. 69A depicts a rear perspective view of an exemplary twelfthproximal wedge used in an exemplary expandable fusion device.

FIG. 69B depicts a section view of an exemplary twelfth proximal wedgeused in an exemplary expandable fusion device.

FIG. 70A depicts a front view of an exemplary twelfth distal wedge usedin an exemplary expandable fusion device.

FIG. 70B depicts a section view of an exemplary twelfth distal wedgeused in an exemplary expandable fusion device.

FIG. 71 depicts a perspective view of an exemplary twelfth expandablefusion device in an initial collapsed state and assembled with atensioner instrument.

FIG. 72A Depicts a section view of an exemplary twelfth expandablefusion device in an initial collapsed state assembled with tensionerinstrument.

FIG. 72B Depicts a section view of an exemplary twelfth expandablefusion device in an expanded state assembled with tensioner instrument.

FIG. 72C Depicts a section view of an exemplary twelfth expandablefusion device in an expanded state with tension member locked in place.

FIG. 73A depicts a top view of an exemplary thirteenth expandable fusiondevice in the initial collapsed state.

FIG. 73B depicts a top view of an exemplary thirteenth exemplaryexpandable fusion device in a fully width expanded state.

FIG. 73C depicts a perspective view an exemplary thirteenth expandablefusion device in the fully height expanded state.

FIG. 73D depicts an exploded view of an exemplary thirteenth expandablefusion device.

FIG. 74A depicts a perspective view of an exemplary thirteenthexpandable fusion device attached to an exemplary inserter-expanderinstrument in the initial collapsed state.

FIG. 74B depicts a perspective view of an exemplary thirteenthexpandable fusion device attached to an exemplary inserter-expanderinstrument in the fully width expanded state.

FIG. 75A depicts a top view of an exemplary fourteenth expandable fusiondevice in the initial collapsed state.

FIG. 75B depicts a top view of an exemplary fourteenth expandable fusiondevice in the fully width expanded state.

FIG. 75C depicts a perspective view of an exemplary fourteenthexpandable fusion device in the fully height expanded state.

FIG. 75D depicts a perspective view of an exemplary fourteenthexpandable fusion device in the fully width and height expanded state.

FIG. 75E depicts an exploded view of an exemplary fourteenth expandablefusion device.

FIG. 76A depicts a top view of an exemplary fifteenth expandable fusiondevice in the initial collapsed state.

FIG. 76B depicts a top view of an exemplary fifteenth expandable fusiondevice in the fully width expanded state.

FIG. 76C depicts a perspective view of an exemplary fifteenth expandablefusion device in a fully width and height expanded state.

FIG. 76D depicts an exploded view of an exemplary fifteenth expandablefusion device.

FIG. 77A depicts a perspective view of an exemplary fifteenth expandablefusion device attached to the inserter-expander instrument in theinitial collapsed state.

FIG. 77B depicts a perspective view of an exemplary fifteenth expandablefusion device attached to the inserter-expander instrument in the fullywidth expanded state.

FIG. 78 depicts a perspective view of an exemplary sixteenth expandablefusion device in the initial collapsed state.

FIG. 79A depicts a perspective view of an exemplary sixteenth expandablefusion device attached to the inserter-expander instrument in theinitial collapsed state.

FIG. 79B depicts a perspective view of an exemplary sixteenth expandablefusion device attached to the inserter-expander instrument in the fullywidth expanded state.

FIG. 80 depicts a top schematic view of an exemplary seventeenthexpandable fusion device outlining its initial and width expandedconfigurations.

FIG. 81A depicts a perspective view of an exemplary eighteenthexpandable fusion device in its expanded state.

FIG. 81B depicts a perspective view of an exemplary eighteenthexpandable fusion device in its collapsed state.

FIG. 81C depicts a perspective view of an exemplary eighteenthexpandable fusion device in an exploded state.

FIG. 82 depicts a perspective view of an exemplary actuator of theeighteenth expandable fusion device.

FIG. 83A depicts a perspective view of an exemplary proximal wedge ofthe eighteenth expandable fusion device.

FIG. 83B depicts a perspective view of an exemplary distal wedge of theeighteenth expandable fusion device.

FIG. 84A depicts a first perspective view of an exemplary proximal rampof the eighteenth expandable fusion device.

FIG. 84B depicts a second perspective view of an exemplary proximal rampof the eighteenth expandable fusion device.

FIG. 85 depicts a perspective view of an exemplary distal ramp of theeighteenth expandable fusion device.

FIG. 86 depicts a perspective view of an exemplary endplate of theeighteenth expandable fusion device.

FIG. 87A depicts a perspective view of an exemplary nineteenthexpandable fusion device in its expanded state.

FIG. 87B depicts a perspective view of an exemplary nineteenthexpandable fusion device in its collapsed state.

FIG. 87C depicts a perspective view of an exemplary nineteenthexpandable fusion device in an exploded state.

FIG. 88 depicts a perspective view of an exemplary actuator of thenineteenth expandable fusion device.

FIG. 89A depicts a perspective view of an exemplary distal wedge of anexemplary nineteenth expandable fusion device.

FIG. 89B depicts a perspective view of an exemplary distal wedge of anexemplary nineteenth expandable fusion device.

FIG. 90A depicts a perspective view of an exemplary first ramp of anexemplary nineteenth expandable fusion device.

FIG. 90B depicts a perspective view of an exemplary first ramp of anexemplary nineteenth expandable fusion device.

FIG. 91A depicts a perspective view of an exemplary second ramp of anexemplary nineteenth expandable fusion device.

FIG. 91B depicts a perspective view of an exemplary second ramp of anexemplary nineteenth expandable fusion device.

FIG. 92A depicts a perspective view of an exemplary first endplate of anexemplary nineteenth expandable fusion device.

FIG. 92B depicts a perspective view of an exemplary first endplate of anexemplary nineteenth expandable fusion device.

FIG. 93A depicts a perspective view of an exemplary second endplate ofan exemplary nineteenth expandable fusion device.

FIG. 93B depicts a perspective view of an exemplary second endplate ofan exemplary nineteenth expandable fusion device.

FIG. 94A depicts a perspective view of an exemplary third endplate of anexemplary nineteenth expandable fusion device.

FIG. 94B depicts a perspective view of an exemplary third endplate of anexemplary nineteenth expandable fusion device.

FIG. 95A depicts a perspective view of an exemplary fourth endplate ofan exemplary nineteenth expandable fusion device.

FIG. 95B depicts a perspective view of an exemplary fourth endplate ofan exemplary nineteenth expandable fusion device.

FIG. 96A depicts a perspective view of an exemplary nineteenthexpandable fusion device and an exemplary separated inserter tool.

FIG. 96B depicts a perspective view of an exemplary nineteenthexpandable fusion device and an exemplary adjoined inserter tool.

FIG. 97 depicts a cross sectioned view of an exemplary nineteenthexpandable fusion device and an exemplary adjoined inserter tool.

FIG. 98A depicts a perspective view of an exemplary twentieth expandablefusion device in its collapsed state.

FIG. 98B depicts a perspective view of an exemplary twentieth expandablefusion device in an exploded state.

FIG. 99 depicts a top view of an exemplary twenty-first expandablefusion device.

DETAILED DESCRIPTION

The following description of the various embodiments is merely exemplaryin nature and is in no way intended to limit the teachings, theirapplications, or uses. While the following description is directedgenerally towards embodiments of the expandable fusion device and methodfor its implantation between two adjacent lumbar vertebrae using alateral, posterior and transforaminal approaches to spine, it would beappreciated that similar mechanisms and arrangements of the same arealso used in treatment of cervical, thoracic and sacral spine segments,utilizing other surgical approaches including but not limited totranspedicular, transiliac, anterior and anterior-lateral approaches andconfigured to interface with respective anatomies and approach angles.Similarly, while the following description is directed generally towardsembodiments of the expandable fusion device in which an actuator drawswedges together to cause expansion, it would be appreciated that inother embodiments the same functionality can easily be achieved throughactuator forcing the wedges apart. A spinal fusion is typically employedto eliminate pain caused by the motion of degenerated disk material.Upon successful fusion, a fusion device becomes permanently fixed withinthe intervertebral disc space.

First Expandable Fusion Device

An exemplary embodiment of a first expandable fusion device 1000 isshown, per FIG. 1, in an initial collapsed state implanted betweenendplates 6 and 8 of adjacent vertebral bodies 2 and 4 through asurgical corridor 5. Implanting the first expandable fusion device 1000in the initial collapsed state reduces the impaction force and the sizeof the surgical corridor 5 required for implantation. Per FIG. 2, thefirst expandable fusion device 1000 is shown in an expanded state(expanded in both width and height) implanted between adjacent vertebralbodies 2 and 4 through the surgical corridor 5 and engaging theendplates 6 and 8. The first expandable fusion device 1000 expands inheight from about 8 mm to about 13 mm or more preferably from 8 mm to 16mm or most preferably from 7 mm to 14 mm and in width from about 10 mmto about 18 mm and more preferably from about 11 mm to about 20 mm andmore preferably from about 14 mm to about 24 mm or most preferably fromabout 15 mm to about 26 mm. The first expandable fusion device 1000 willpreferably be longer than it is wide in its initial collapsed state andthe endplates will preferably be longer than they are wide. Expandingthe fusion device 1000 while implanted between the vertebral bodies 2and 4 allows an increase in the width of the fusion device 1000 and thespacing or contact area (or foot-print) between the fusion device 1000and the endplates 6 and 8 beyond that, which would otherwise be allowedby the surgical corridor 5 as well as application of distraction forcesto the endplates 6 and 8 in order to preferably increase and maintainthe distance and/or angle between the vertebral bodies 2 and 4, byincreasing and maintaining the height of the implant and/or the angularorientation of its components.

The components of the first expandable fusion device 1000 may be madeout of a variety of materials including but not limited to metals andalloys (e. g. Commercially Pure Titanium, Titanium alloys includingTi-6Al-4V based allows, Cobalt alloys including CoCrMo alloys, Stainlesssteel, Tantalum and its alloys, Platinum and its alloys, etc.), polymers(e. g. PEEK, PEKK, PEKEK, PEI, PET, PETG, UHMWPE, PPSU, Acetal,Polyacetal, etc. including carbon fiber reinforced varieties and othervarieties filled, for example, with Carbon Fiber, Carbon nano-tubes,Graphene, Barium Sulfate or Hydroxyapatite), ceramics (e. g. AluminumOxide, Zirconium oxide, Silicon nitride, diamond-like carbon, etc. aswell as various metalized ceramics an metal-ceramic composites).Optionally, in any embodiment, the components of the fusion device 1000are manufactured out of a Titanium alloy (including but not limited toTi-6Al-4V alloys) or a Cobalt alloy including but not limited to CoCrMoalloys. Optionally, in any embodiment, manufacturing some of thethreaded components of the fusion device 1000 out of a CoCr-based alloyallows for increased strength, reduced size, and other performanceconsiderations.

Optionally, in any embodiment, bone allograft, bone autograft, xenogaft,demineralized bone matrix product, synthetic bone substitute, bonemorphogenic agents, or other bone growth inducing material areintroduced within and/or around the fusion device 1000 to furtherpromote and facilitate the intervertebral fusion. In one embodiment, thefusion device 1000 is preferably packed or injected with bone graft,demineralized bone matrix product, synthetic bone substitute, bonemorphogenic agents, or other bone growth inducing material after it hasbeen expanded, but in other embodiments, the graft material may also beintroduced into the space within or around the fusion device 1000 priorto implantation or after the implantation but prior to expansion.

With reference to FIGS. 3-5, an exemplary fusion device 1000 is shown.FIG. 3 shows the fully collapsed state of the fusion device 1000. FIG. 4shows an expanded state of the fusion device 1000. FIG. 5 shows anexploded view of the fusion device 1000. Optionally, in any embodiment,the fusion device 1000 includes a first endplate 100, a second endplate150, a third endplate 200, a fourth endplate 250, a proximal wedge 550,a distal wedge 650, an actuator 500, a first ramp 300, a second ramp350, a third ramp 400, a fourth ramp 450, a retaining pin 600 (best seenin FIG. 5) and a retaining set screw 700. Optionally, in any embodiment,the first endplate 100, the second endplate 150, the third endplate 200,and the fourth endplate 250 are substantially identical, but althoughall four have the same set of features, the specific size and angularorientation of these features do not have to be identical in allembodiments or within any particular embodiment. Optionally, in anyembodiment, the first ramp 300, the second ramp 350, the third ramp 400and the fourth ramp 450 are substantially identical (it should be notedthat the ramps, even while identical in an embodiment, may or need to besuitably rotated or mirrored to be assembled into arrangements shown inFIGS. 3-5), but although all four have the same set of features, thespecific size and angular orientation of these features do not have tobe identical in all embodiments or within any particular embodiment.Furthermore, the effects of the endplates, the ramps and the wedgeshaving their ramped surfaces inclined at different angles on theexpansion characteristics of the fusion device 1000 is illustrated infurther detail below.

As will be discussed in more detail below, the actuator 500 functions,to pull the proximal wedge 550 and distal wedge 650 together forcing thefirst ramp 300 away from the third ramp 400 and also forcing the secondramp 350 away from the fourth ramp 450, which causes the endplates 100and 150 to be forced away from the endplates 250 and 200 (resulting inwidth expansion of the fusion device 1000). Optionally, in anyembodiment, only after the width expansion is substantially complete,the first ramp 300 and the second ramp 350 are pulled toward each otherand the third ramp 400 and the fourth ramp 450 are pulled toward eachother. The movement of the first ramp 300 and the second ramp 350 towardeach other forces the first endplate 100 away from the second endplate150 and the movement of the third ramp 400 toward the fourth ramp 450forces the third endplate 200 away from the fourth endplate 250(resulting in height expansion). The retaining pin 600 and the retainingset screw 700 act in an embodiment to resist the tension in the actuator500 and maintaining the linear position of the proximal wedge 550relative to the actuator 500. Optionally, in any embodiment, asub-assembly comprising the actuator, the proximal wedge, the distalwedge, and the four ramps are collectively referred to as the actuatorassembly.

Optionally, in any embodiment, the ramps 300 and 350 and the ramps 400and 450 only start moving toward each other after the width expansionhas substantially taken place and the ramps 300 and 400 havesubstantially reached the limit of their travel relative to the proximalwedge 550 and the ramps 350 and 450 have substantially reached the limitof their travel relative to the distal wedge 650. Optionally, in anyembodiment, this delay in height expansion is achieved through theendplates 100, 150, 200, 250 being slidably engaged with proximal wedge550 and the distal wedge 650 through an initial portion of widthexpansion process. During the width expansion process, as the wedges 550and 650 move toward each other, they eventually disengage from endplates100, 150, 200, 250 and allow them to expand in height as will bediscussed below. Optionally, in any embodiment, the delay in heightexpansion is further accomplished by means of an inserter instrumentconstraining the height expansion until the width expansion hassubstantially taken place as will be discussed below.

When fully assembled, the first expandable fusion device 1000 is mostpreferably, a stable assembly of components that are all detained withinthe assembly throughout its full range of motion by means of“dove-tailed” articulations, the use of fasteners such as, for example,pins, balls, screws, and set screws. Optionally, in any embodiment, thefasteners are affixed in one component and travel in a mating feature(such as a track) of another component thereby limiting the range ofmotion of the first component to the amount permissible by the trackfeature thereby preventing the components from disassembly.

With reference to FIGS. 6A-6F, FIGS. 6A and 6B show side and end viewsrespectively of the fusion device 1000 in an initial fully collapsedstate, FIGS. 6C and 6D show side and end views respectively of thefusion device 1000 in a fully expanded width state and FIGS. 6E and 6Fshow side and end views respectively of the fusion device 1000 in fullyexpanded width and height state.

FIGS. 7A-7C illustrate a mechanism for delaying the height expansionuntil width expansion is partially or substantially complete. In FIG.7A, the fusion device 1000 is shown in an initial collapsed state anddemonstrates, as an example, the engagement of the proximal wedge 550with mating features of the endplates 100 and 150, in this state,drawing the proximal wedge 550 and the distal wedge 650 together resultsin width expansion but not in height expansion of the fusion device1000. Optionally, in any embodiment, per FIG. 7A, the engagement betweenthe proximal wedge and the endplates prevents height expansion. Oncewidth expansion occurs to a sufficient extent for the wedges todisengage from the mating features on the endplates (shown in FIG. 7B),the further drawing of the proximal wedge 550 and the distal wedge 650together may result in either height only expansion (shown in FIG. 7C)or in simultaneous height and width expansion. Optionally, in anyembodiment, FIG. 7B, the disengagement of the proximal wedge from theendplates allows height expansion. Optionally, in any embodiment,starting width is preferably 14 mm and the height expansion starts whenthe width reaches about 20 mm. Optionally, in any embodiment, the heightexpansion may start when full maximum or substantial (as discussedabove) width is achieved. The delay in height expansion is achievedbecause in order for height expansion to take place, the pairs of rampson either side of the fusion device 1000 have to translate toward eachother relative to the endplates with which they are engaged. This cannotoccur while the ramped surfaces of the wedges are simultaneously engagedwith both the endplates and the ramps since the endplates are rigid andspan the distance between the proximal wedge 550 and the distal wedge650 and thereby only allow the width expansion until the state shown inFIG. 3C is reached, at which point the wedges are still engaged with theramps but are no longer engaged with the endplates and drawing thewedges together from this point onward allows the ramps to move towardeach other relative to the endplates resulting in height expansion.Detailed description of the components and their features is providedbelow.

Although the following discussion relates to the first endplate 100, itshould be understood that it also equally applies to the second endplate150, the third endplate 200 and the fourth endplate 250 as the firstendplate 100 is substantially identical to the second endplate 150, thethird endplate 200 and the fourth endplate 250 in this embodiment (notethat the endplates, even while identical in an embodiment, may or needto be suitably rotated or mirrored to be assembled into arrangementsshown above in the assemblies shown in FIGS. 3-5). The endplates 100 and250 are collectively referred to as the upper endplate and the endplates150 and 200 are collectively referred to as the lower endplate. Itshould also be understood that while the words “substantially identical”refer to the endplates 100, 150, 200 and 250 having the same or similarset of features, all of which features serving the same or similarfunction in each of the endplates 100, 150, 200 and 250 as describedbelow, the specific size and angular orientation of these features mayor may not be identical between the endplates 100, 150, 200 and 250within any particular embodiment.

Turning now to FIGS. 8A and 8B showing respectively the bottom and thetop views of the endplate 100. Optionally, in any embodiment, the firstendplate 100 has a first end 102 and a second end 104. In theillustrated embodiment, the first endplate 100 further comprises anupper surface 134 connecting the first end 102 and the second end 104,and a lower surface 132 connecting the first end 102 and the second end104. Optionally, in any embodiment, the first endplate 100 furthercomprises two tapered slots, a first tapered slot 107 proximate thefirst end 102, extending from the lower surface 132 toward the uppersurface 134 and a second tapered slot 109 proximate the second end 104,extending from the lower surface 132 toward the upper surface 134.Optionally, in any embodiment, the slopes or shapes of the tapered slots107 and 109 are equal or differ from each other.

The first tapered slot 107 comprises a bottom surface 106, which issubstantially parallel to the long axis in an embodiment, but may alsobe angled or curved in the plane transverse to the long axis in otherembodiments, a tapered surface 110 generally transverse to the bottomsurface 106 and a tapered surface 136 opposite of the tapered surface110 and generally transverse to the bottom surface 106, whereas thetapered surfaces 110 and 136 taper toward each other from bottom surface106 and toward the inward surface 130. The second tapered slot 109comprises a bottom surface 108, which is substantially parallel to thelong axis in an embodiment, but may also be angled or curved in theplane transverse to the long axis in other embodiments, a taperedsurface 138 generally transverse to the bottom surface 108 and a taperedsurface 112 opposite of the tapered surface 138 and generally transverseto the bottom surface 108, whereas the tapered surfaces 138 and 112taper toward each other from bottom surface 108 and toward the inwardsurface 130.

Endplate 100 further optionally comprises a first relief 125 forming aplanar surface 126 and a second relief 127 forming a planar surface 128.The first relief 125 extending from the first end 102 to the firsttapered slot 107 and defined by the planar surface 126 substantiallyparallel to the lower surface 132 and a first relief surface 114substantially planar and parallel to the inward surface 130. The secondrelief 127 extending from the second end 104 to the second tapered slot109 and defined by a planar surface 128 substantially parallel to thelower surface 132 and a second relief surface 116 substantially planarand parallel to the inward surface 130. Optionally, in any embodiment,the endplate 100 includes a first chamfer 142 proximate the first end102 and the second chamfer 144 proximate the second end 104. Chamfers142 and 144 preferably facilitate introduction and removal of fusiondevice 1000 between the adjacent vertebral bodies 2 and 4 by reducingthe height of the endplate 100 at first end 102 and the second end 104thereby providing a tapered leading and trailing edges.

Optionally, in any embodiment, the endplate 100 further optionallycomprises ramped grooves 122 and 118 proximate the first end 102 andramped grooves 124 and 120 proximate the second end 104. The rampedgrooves 122, 118 and 124, 120 are configured to engage the mating rampedgeometry of the proximal wedge 550 and the distal wedge 650 to cause theinitial expansion of the fusion device 1000 to be limited to widthexpansion and to prevent the fusion device 1000 from expanding in widthand height simultaneously. The slopes of the ramped grooves 122, 118,124 and 120 are configured to match those of the wedges 550 and 650.Ramped grooves 124 and 122 are configured to mate with the geometry ofthe trapezoidal (or in other embodiments T-shaped, Y-shaped, etc.)projections of the wedges 550 and 650. The ramped grooves 118 and 120are preferably each formed by two surfaces, one parallel to the bottomsurface 132, and one perpendicular to it. The ramped grooves 118 and 120are configured to mate with the protuberances of the projections of thewedges 550 and 650.

Turning now to FIGS. 9A-9E. It should be understood that although in theillustrative embodiment, the slots 107 and 109 have trapezoidalcross-sections, they can optionally have but are not limited to thefollowing, T-shaped cross-section (shown in FIG. 9A), L-Shapedcross-section (shown in FIG. 9B), Y-shaped cross-section (shown in FIG.9C), F-shaped cross-section (shown in FIG. 9D) or generally anycross-section that preferably results in the slots 107 and 109 beingnarrower at the inward surface 130 than they are at the bottom surfaces106 and 108 or at any point in between the inward surface 130 and thebottom surfaces 106 and 108. Optionally, in any embodiment, while theshapes described above are preferable when retention of the ramp 300 inthe endplate 100 is desired by means of “dove-tailed”, tapered, T-shapedor otherwise slot geometry, a non-tapered, generally rectilinearcross-section (shown in FIG. 9E) of the slots 107 and 109 are beneficialfor example when an additional fastener (e. g. pin or set screw) areused to retain the ramp 300 in the slots 107 or 109 to only allowtranslation in one dimension (while rotation in one or more planes mayalso be allowed). It should also be understood that although the variousalternative geometries of the endplates are presented here as discreteembodiments, these alternative embodiments have optional features whichmay be substituted or mixed/matched with any other embodiment in thespecification. It should also be understood that substituting any of theaforementioned optional alternative features in the endplate componentmay or will necessitate the mating components (e. g. the endplates, theramps and the wedges) to use the inverse or complementary geometry ofthose features for proper engagement and that the shape of that inverseor complementary geometry would follow inevitably from the optionalalternative feature geometry described above.

FIGS. 10A-10D3 show alternative embodiments of the endplate 100. FIGS.10A and 10B show an exemplary endplate 100 in which the lower surface132 further includes a projection 145 sharing the tapered surface 110with the first tapered slot 107 and a projection 146 sharing the taperedsurface 112 with the second tapered slot 109. In the embodiment of FIGS.10A and 10B, the lower surface 132 further includes a recess 147configured to accept the projection 146 of another endplate and a recess148 configured to accept the projection 145 of another endplate. Thepurpose of the projections 145 and 146 and the recesses 147 and 148 isto increase the contact area and provide additional stability betweenthe endplates 100, 150, 200, 250 and the ramps 300, 350, 400, 450 whenthe fusion device 1000 approaches maximum height expansion state (shownin FIG. 10C below). In embodiments without the projections 145 and 146,as the fusion device 1000 expands in height, the contact area betweenthe endplates and the ramps steadily decreases as the ramps translatethrough the tapered slots of the endplates to produce expansion. Theprojections 145 and 146 compensate for this loss of contact area therebyimproving the stability of the fusion device 1000 assembly. It should beunderstood that the same embodiments discussed above and shown in toFIGS. 9A, 9B, 9C, 9D would equally apply to the embodiments shown inFIGS. 10A and 10B. Optionally, in any embodiment, some of the areaswhere the projections 145 and 146 generate additional contact areabetween the endplates and the ramps. Furthermore, Optionally, in anyembodiment, the projections 145 and 146 and the mating recesses 147 and148 though pictured as generally triangular in an embodiment, may haveother shapes that accomplish the same goal of increasing the contactarea between the endplates 100, 150, 200, 250 and the ramps 300, 350,400, 450 as the fusion device 1000 approaches maximum height expansionstate. FIG. 10C shows a fully expanded state of an exemplary fusiondevice 1000 that includes the projections 145 and 146 as well as themating recesses 147 and 148 on the endplates. Some of the areas wherethe projections generate additional contact area between the endplatesand the ramps are indicated and labeled. FIGS. 10D1-10D3 show anexemplary fusion device 1000 in which the endplate 100 includes aprotrusion 143 on its proximal end. The protrusion 143 further includesan aperture 149 configured to accept a bone fastener 730. The anglebetween the central axis of the aperture 149 and the long axis of theendplate 100 may have any value between 0 and 90 degrees but mostpreferably between 0 and 45 degrees and generally (but not necessarilyin embodiments where the proximal portion of the bone fastener 730 (i.e. the “head” of the fastener 730) in contact with the protrusion 143 issubstantially greater than that of the main body of the bone fastener730 contacting bone (i. e. the shank of the fastener 730) and where themain body is substantially smaller than the aperture 149) defines thetrajectory of the bone fastener 730, shown assembled with the fusiondevice 1000 in FIG. 10D3. It should be understood that although thevarious alternative geometries of the endplates are presented here asdiscrete embodiments, these alternative embodiments have optionalfeatures which may be substituted or mixed/matched with any otherembodiment in the specification. It should also be understood thatsubstituting any of the aforementioned optional alternative features inthe endplate component may or will necessitate the mating components (e.g. the endplates, the ramps and the wedges) to use the inverse orcomplementary geometry of and to those features for proper engagementand that the shape of that inverse or complementary geometry wouldfollow inevitably from the optional alternative feature geometrydescribed above.

As illustrated in FIGS. 11A-12D, Optionally, in any embodiment, perFIGS. 11A, 11D, and 12A, the upper surface 134 of the first endplate 100is generally planar to allow the upper surface 134 of the first endplate100 to engage with the adjacent vertebral body 2. Alternatively, theupper surface 134 are curved in one or more planes (shown in FIGS. 11B,11C, 11F, 11H, and 12B) to allow for a greater degree of engagement withthe adjacent vertebral body 2. Optionally, in any embodiment, the uppersurface 134 are generally planar but include a generally straight rampedsurface (shown in FIGS. 11G and 12C) or a curved ramped surface (shownin FIGS. 11E, 11I and 12D). The ramped surface allows for engagementwith the adjacent vertebral body 2 in a lordotic fashion as shown forexample in FIG. 11E and/or for example in a coronally tapered fashion asshown for example in FIGS. 12C and 12D. Optionally, in any embodiment,an arrangement of non-ramped endplates of different heights as well asramped and non-ramped endplates of different heights also results in ageometry suitable for lordotic engagement with the endplates, which areseen illustrated in FIGS. 11D, 11F, 11H, and 11I). It should beunderstood that since the FIGS. 11A-11I and FIGS. 12A-12D show thedevice 1000 in two different projections 90 degrees from each other, theramped quality of the surface 134 is described as “lordotic” for FIGS.11A-11I and as “tapered” for FIGS. 12A-12D. It is further contemplatedthat although in one embodiment, all endplates in the fusion device 1000have the same length, in other embodiments, some or all of the endplatesmay have different lengths to better accommodate the target anatomy.FIGS. 13A and 13C show a fully collapsed and fully expanded views of anexemplary fusion device 1000 in which all endplates have the same lengthand FIGS. 13B and 13D show an exemplary fusion device 1000 in which twoof the endplates have shorter length than the other two, which is seenas advantageous in lateral approach applications as well as in someposterior approach applications. Optionally, in any embodiment, theupper surface 134 includes texturing 140 to aid in gripping the adjacentvertebral bodies. Although In the illustrated embodiment, the texturing140 comprises series of parallel grooves running transversely to thelong axis of the endplate 100, including but is not limited to thefollowing, the texturing includes teeth, ridges, areas of high surfaceroughness, metallic or ceramic coatings with relatively high surfaceroughness, friction increasing elements, keels, spikes, or gripping orpurchasing projections. Optionally, in any embodiment, one or more ofthe endplates are shorter, longer, narrower, or wider than others. Itshould be understood that although the various alternative geometries ofthe endplates are presented here as discrete embodiments, thesealternative embodiments have optional features which may be substitutedor mixed/matched with any other embodiment in the specification. Itshould also be understood that substituting any of the aforementionedoptional alternative features in the endplate component may or willnecessitate the mating components (e. g. the endplates, the ramps andthe wedges) to use the inverse and/or complementary geometry of/to thosefeatures for proper contemplated engagement between the variouscomponents of the fusion device 1000 and between those components andthe surrounding anatomy and that the shape of that inverse and/orcomplementary geometry would follow inevitably from the optionalalternative feature geometry described above.

The effect of varying the slopes and/or the orientations of the taperedslots 107 and 109 or the amount of travel allowed between the ramps andthe tapered slots 107 and 109 are seen illustrated in FIGS. 14A-14B2.FIG. 14A shows the effects of varying the slopes and/or the orientationof the slots 107 and 109 on each of the four endplates viewed from theside where the top of the device 1000 is represented by the endplate 250and the bottom of the device is represented by the endplate 200. Varyingthe slopes of the slots 107 and 109 or limiting the allowable travelbetween the ramps and the slots 107 and 109 within each of the endplatesmay result, but is not limited to the first ends 102 and the second ends104 expanding evenly on both top and bottom of the fusion device 1000,expanding unevenly on both top and bottom, expanding evenly on top andunevenly on bottom or expanding evenly on bottom and unevenly on top ofthe fusion device 1000. FIGS. 14B1 and 14B2 show a respectively theinitial fully collapsed and an expanded view of an exemplary fusiondevice 1000 configured to expand unevenly at its proximal and distalends, leading to an expanded state in which the endplates are taperingat an angle. The embodiment of FIGS. 14B1 and 14B2 employs analternative embodiment of the ramp 300 (discussed in detail below)suitable for uneven expansion between one end of the endplate and theother end of the endplate by means of allowing the tapered slots 107 and109 to make contact with circular surfaces instead of the flat rampedsurfaces of other embodiments, which in turn allows the long axes of theendplates to be at an angle to the long axes of the ramps. Theembodiment of FIGS. 14B1 and 14B2 further employs a mechanism, describedin detail below, which independently limits the amount of travel betweenthe ramp and the tapered slot 107 and the ramp and the tapered slot 109,which allows, for example, the proximal end of the endplate to reach theend of its height expansion and therefore stop expanding before thedistal end of the endplate does, resulting in the distal end of theendplate continuing expanding after the proximal end has stoppedexpanding thereby achieving greater height expansion than the proximalend at the fully expanded state.

Turning now to FIGS. 15A-15G, the effects of varying the slope and/ororientation of the ramped grooves 122, 118, 124 and 120 of the endplate100 as well as the slopes and/or orientations of the complementarymating features of the ramps and the wedges are shown. FIG. 15A shows anend view of the fusion device 1000, where the top of the device 1000 isrepresented by the endplates 100 and 250 and the bottom of the device isrepresented by the endplates 150 and 200. FIG. 15A shows an embodimentin which both sides of the fusion device 1000 expand evenly and anembodiment in which left and right sides expand unevenly. FIGS. 15B, 15Cand 15D show an exemplary fusion device 1000 in which the left and rightsides of the fusion device 1000 expand unevenly due to the variation ofthe slopes of the mating ramped features of the endplates, the wedgesand the ramps. FIG. 15B shows the top view of the collapsed state of theembodiment, FIG. 15C shows the top view of the expanded state of theembodiment and schematically indicates the amounts of width expansionachieved in each direction, which are unequal. FIG. 15D shows aperspective view of the expanded state of the embodiment and allows abetter view of the difference in the slopes of the ramped surfacesbetween the two sides of the fusion device 1000. FIG. 15E further showsan exemplary distal wedge 650 used in the assembly 1000 shown in FIG.15D. FIG. 15F further shows an exemplary proximal wedge 550 used in theassembly 1000 shown in FIG. 15D. FIG. 15G further shows an exemplaryramp 300 used in the assembly 1000 shown in FIG. 15D. Turning now toFIG. 16, which shows the end views of four embodiments of the fusiondevice 1000 illustrating the effects of varying the slopes of the slots107 and 109 between the endplates but keeping them the same within eachindividual endplate, which may result but is not limited to all fourendplates expanding at the same rate, all four endplates expanding atdifferent rates, any three endplates expanding at the same rate, whilethe fourth expands at a different rate, any two endplates expanding atone rate, while the other two expand at a different rate. Furthermore,curving the slots 107 and 109 in the plane transverse to the long axisof any of the endplates will preferably cause those endplates to tiltduring expansion as shown in FIG. 16. It should be understood thatalthough the various alternative geometries of the endplates, thewedges, and the ramps are presented here as discrete embodiments, thesealternative embodiments have optional features which may be substitutedor mixed/matched with any other embodiment in the specification. Itshould also be understood that substituting any of the aforementionedoptional alternative features in one component may or will necessitatethe mating components (e. g. the endplates, the ramps and/or the wedges)to use the inverse and/or complementary geometry of those features forproper contemplated engagement between all of the various components ofthe fusion device 1000 and between those components and the surroundinganatomy and that the shape of that inverse and/or complementary geometrywould follow inevitably from the optional alternative feature geometrydescribed above.

Although the following discussion relates to the first ramp 300, itshould be understood that it also equally applies to the second ramp350, the third ramp 400 and the fourth ramp 450 as the first ramp 300 issubstantially identical to the second ramp 350, the third ramp 400 andthe fourth ramp 450 in embodiments of the present disclosure (note thatthe ramps, even while identical in an embodiment, may or need to besuitably rotated to be assembled into arrangements shown above in theassemblies shown in FIGS. 3-5). It should also be understood that whilethe words “substantially identical” refer to the ramps 300, 350, 400 and450 having the same set of features, all of which features serving thesame or similar function in each of the ramps 100, 150, 200 and 250 asdescribed below, the specific size and angular orientation of thesefeatures may or may not be identical between the ramps 300, 350, 400 and450 within any particular embodiment.

Turning now to FIGS. 17A and 17B, in an embodiment, the first ramp 300has a first end 301 and a second end 303. In the illustrated embodiment,the first ramp 300 further comprises an inner surface 305 connecting thefirst end 301 and the second end 303, and an outer surface 307 (bestseen in FIG. 17B) connecting the first end 301 and the second end 303.The first ramp 300 further comprises an upper surface 309 connecting thefirst end 301 and the second end 303, and a lower surface 311 connectingthe first end 301 and the second end 303, the two surfaces 309 and 311being preferably but not necessarily parallel to each other. The firstramp 300 further comprises a protuberance 315 further comprising anupper branch 321 extending preferably but not necessarily past the outersurface 307 and the lower surface 311, and a lower branch 323 extendingpreferably but not necessarily past the outer surface 307 and the lowersurface 311. The upper branch 321 comprises a first ramped surface 302and a second ramped surface 310, which extend from the inner surface 305and taper outward in the direction of outer surface 327, giving theupper branch 321 a generally trapezoidal cross-section. The lower branch323 comprises a first ramped surface 304 and a second ramped surface 312which extend from the inner surface 305 and taper outward in thedirection of the outer surface 327, giving the lower branch 323 agenerally trapezoidal cross-section. The branches 321 and 323 arecontemplated to slidably engage the tapered slots 107 and 109 in the endplates. The mating cross-sections of the branches 321 and 323 and thetapered slots 107 and 109 are contemplated to be configured to onlyallow translation in one dimension, either in a straight or a curvedline (though some embodiments may allow rotation in one or more planes).

As a rest be seen in FIG. 17A, the inner surface 305 includes aprojection 319 forming a ramped surface 320 and a surface 325 thatpreferably form angles greater than 90 degrees with the inner surface305, as FIG. 17A shows. The projection 319 includes a first branch 314and a second branch 316 and a groove 322. The groove 322 extends fromthe outer surface 307, along the ramped surface 320 and toward the innersurface 305. The groove 322 does not extend through the surface 325instead terminating in a surface 324. As will be discussed below, thepurpose of the channel 322 and the surface 324 is to limit the motion ofthe proximal wedge 550 and the distal wedge 650 with respect to the ramp300 by causing a mating feature on the ramp 300 to bottom out on thesurface 324. The channel 322 may further include a blind bore 308 whichis coincident with the surface 324. The purpose of the bore 308 is tooptionally accept a mating pin to limit the amount of width expansionallowable. The branch 314 extends from the ramped surface 320 to asurface 329 and the branch 316 extends from the ramped surface 320 to asurface 330. The projection 319 further includes a relief 306 whose axisis substantially parallel to the long axis. The relief 306 is configuredto mate with the actuator 500 and allow the ramps to be in closerproximity to each other than would otherwise be possible without therelief 306. The relief 306 has any cross-section suitable to accomplishthe function described above, for example a generally rectilinearcross-section or more preferably a partially polygonal cross-section ormost preferably a circular cross-section. The ramped surface 320 and thebranches 314 and 316 form a tapered channel 328, which has a generallytrapezoidal cross-section. It should be understood that although in theillustrative embodiment, the tapered channel 328 has a trapezoidalcross-section, the cross section may comprise, is not limited to, aT-shaped cross-section (shown in FIG. 18C), a Y-Shaped cross-section(shown in FIGS. 18D and 18E), an L-shaped cross-section (not shown), anF-shaped cross-section (not shown) or generally any cross-section thatpreferably results in the tapered channel 328 being narrower at asurface 329 than it is at the ramped surface 320 or at any point inbetween the surface 329 and the ramped surface 327. Optionally, in anyembodiment, the slope of the ramped surface 320 may or may not be thesame between the ramps 350, 400, 450, 500 in the end plates.

It should be understood that although in the illustrative embodiment,the branches 321 and 323 have trapezoidal cross-section, they can havebut are not limited to the following, T-shaped cross-section, Y-Shapedcross-section, L-shaped cross-section or generally any cross-sectionthat preferably results in the branches 321 and 323 being narrower atthe inner surface 305 than they are at the outer surface 327 or at anypoint in between the inner surface 305 and the outer surface 327. FIGS.18A, 18B, 18C, 18D, 18E show a number of cross-sections that thebranches 321 and 323 may take. Any embodiment described herein mayoptionally have these cross-sections in their branches. L-shaped (FIG.18A), U-shaped (FIG. 18B) and T-shaped (FIG. 18C) cross-sections may beparticularly preferable due to manufacturability considerations, but theY-shaped cross-section (FIG. 18D) and an “Inside-T” shaped cross-section(FIG. 18E) are also possible. Optionally, in any embodiment, the slopesof the branches 321 and 323 are equal or differ from each other. Sincethe branches 321 and 323 are intended to mate with slots 107 and 109,the effects of varying their slopes is the same as discussed above forthe slots 107 and 109 in the endplate 100. Likewise, the effects ofvarying the slope of the ramped surface 320 between each of the fourramps on the expansion characteristics of the device 1000 has beendescribed above and are seen above in FIGS. 15A-15G, but to add to thedescription of these figures and in light of the detailed description ofthe ramp 300 specification provided here, it should be mentioned thatsince the slope of the ramped surface 320 controls the width expansionof the device 1000, varying its slope in each of the ramps (as well asvarying the mating slopes of the ramps in the wedges in complementaryfashion) may result in but is not limited to all four endplatesexpanding at the same rate, the endplates on the right side expandingfaster than the endplates on the left side and the endplates on the leftside expanding faster than the endplates on the right side or one, someor all of the endplates expanding faster than the others. It should beunderstood that although the various alternative geometries of the rampsmay be presented here as discrete embodiments, these alternativeembodiments have optional features which may be substituted ormixed/matched with any other embodiment in the specification. It shouldalso be understood that substituting any of the aforementioned optionalalternative features in the ramp component will necessitate the matingcomponents (e. g. the endplates, the wedges and/or the actuator) to usethe inverse or complementary geometry of those features for properengagement and that the shape of that inverse or complementary geometrywould follow inevitably from the optional alternative feature geometrydescribed above.

Turning now to FIGS. 19A-19H2, where the FIGS. 19A and 19B show analternative embodiment of the ramp 300 in which the branches 321 and 323comprise generally cylindrical (in other contemplatedembodiments—conical) protrusions 331 and 332 respectively with theircentral axes generally perpendicular to the long axis of the ramp 300.Optionally, in any embodiment, the protrusions 331 and 332 furtherinclude apertures 334 and 335 respectively. The apertures 334 and 335have their central axes coincident with the central axes of theprotrusions 331 and 332 and said apertures are configured to engage afastener 740, which in an embodiment is a pin (but in other embodimentsis a screw) configured to engage the apertures 334 and 335 as well as atrack 127A (best seen in FIG. 19H2) extending into the bottom surface108 of the endplate 100 and a corresponding track (not shown) extendinginto the bottom surface 106 of the endplate 100. The fasteners 740 whenengaged into the corresponding tracks in the endplate 100 are intendedto equally or preferentially limit the amount of translation allowedbetween the ramp 300 and the ramped slots 107 and 109 in the endplate100. It should be understood that although in the illustrativeembodiment, the protrusions 331 and 332 have generally rectangularcross-sections through their central axes, or cross sections includingbut not limited to, L-shaped cross-section (shown in FIGS. 19C and 19D),T-Shaped cross-section (shown in FIGS. 19E and 19F), trapezoidalcross-section (not shown) or generally any cross-section that preferablyresults in the protrusions 331 and 332 being narrower at the innersurface 305 than they are at the outer surface 327 or at any point inbetween the inner surface 305 and the outer surface 327. Thearticulation between these embodiments of the ramp 300 and the endplate100 is intended to allow the ramp 300 to translate in the ramped slots107 and/or 109 of the endplate 100 in only one dimension and to rotatewithin said slots in only one plane.

FIGS. 19G1-19G3 show section views of the assembly of an embodiment ofarticulation of an exemplary endplate 100 and an exemplary ramp 300 inwhich the ramp 300 is translationally limited within the ramped slot ofthe endplate 100 at one angle formed between the long axes of the ramp300 and the endplate 100 while being allowed to pass (for example andpreferably during assembly of the fusion device 1000) at another angle(preferably outside the functional and/or useful range of an exemplaryfusion device 1000) between the long axes of the ramp 300 and theendplate 100 due to a T-slot 149 being a blind slot and not breakingthrough the bottom surface 132 of the endplate 100. FIGS. 19H1 and 19H2show a portion of an exemplary fusion device 1000 including anembodiment of articulation between the ramp 300 and the endplate 100 inwhich the ramped slot 109 of the endplate 100 has a generally T-shapedcross-section and in which the protrusion 331 of the ramp 300 has agenerally T-shaped cross-section. The protrusion 331 further includesthe aperture 334 generally concentric with it, where the aperture 334 isconfigured to accept the fastener 740, which in this embodimentcomprises a pin. The ramped slot 107 of the endplate 100 furthercomprises a track recessed into its bottom surface and configured toengage the fastener 740 with the purpose of limiting the translationaltravel of the ramp 300 inside the slot 107 of the endplate 100. FIG.19H1 shows the side view of the assembled articulation and FIG. 19H2shows the exploded view of the articulation. Both the embodiments ofFIGS. 19G1-19G3 and FIGS. 19H1-19H2 are contemplated as useful for, butnot limited to, producing uneven expansion of the distal and proximalends of the fusion device 1000 shown in FIGS. 14B1 and 14B2 above. Itshould be understood that although the various alternative geometries ofthe ramps are presented here as discrete embodiments, these alternativeembodiments have optional features which may be substituted ormixed/matched with any other embodiments in the specification. It shouldalso be understood that substituting any of the aforementioned optionalalternative features in one component may or will necessitate the matingcomponents (e. g. the endplates, the wedges and/or the actuator) to usethe inverse and/or complementary geometry of those features for properintended engagement between both the various components of the fusiondevice 1000 and between those components and the surrounding anatomy andthat the shape of that inverse and/or complementary geometry wouldfollow inevitably from the optional alternative feature geometriesdescribed above.

Turning now to FIG. 20. The actuator 500 comprises a proximal end 504, adistal end 502, and a cylindrical surface 506 connecting the proximalend 504 and the distal end 502. Optionally, in any embodiment, theactuator 500 further comprises a drive feature 512 proximate theproximal end 504 and a thread 508 proximate the distal end 502. Thecylindrical surface 506 includes a groove 514 circumferentially disposedaround the actuator proximate the drive feature 512 and a ridge 510circumferentially disposed around the actuator proximate the thread 508.The ridge 510 is contemplated to serve as a depth stop to limit thelinear travel of the actuator 500 by making contact with the distalwedge 650 at the end of allowable travel range. Although in anembodiment, the drive feature 512 is shown as an hexalobular protrusion(external hexalobe drive), Optionally, in any embodiment, the drivefeature 512 may be but is not limited to internal hexalobe, externalhexagon, internal hexagon, external cruciform, internal cruciform or anyother shape. Optionally, in any embodiment shown in FIG. 21A, the drivefeature 512 is a hexagonal recess (internal hexagon drive).Additionally, in the embodiment shown in FIG. 21A, the cylindricalsurface 506 of the actuator 500 further includes a ridge 515circumferentially disposed around the actuator proximate the proximalend 504, but distal to the groove 514. The ridge 515 is configured tobottom out on the second end 560 of the proximal wedge 550 and iscontemplated to provide resistance to the actuator 500 pushing throughthe central aperture 568 and subjecting the retaining pin 600, theretaining set screw 700, a retaining c-clip 720 or some other actuatorretention means to high loads. FIG. 25 shows a section view of asub-assembly including the proximal wedge 550, the actuator 500, and theretaining c-clip 720 and demonstrates the location and function of theridge 515. Optionally, in any embodiment shown in FIG. 21B, the actuator500 comprises an additional thread 517 proximate the proximal end 504.The thread 517 is comprised of a helical groove of opposite direction tothat of the thread 508 (i. e. if the thread 508 is right-handed, thenthe thread 517 is left-handed). The effect of addition of the opposingdirection thread 517 is that the actuator 500 would thread into thedistal wedge 650 in a for example clock-wise fashion while threadinginto the proximal wedge 550 in, for example, a counter-clock-wisefashion, which causes the actuator 500 to draw the wedges together whilealso translating relative to both wedges when torsionally actuated. Theextent of travel of the actuator 500 relative to each of the wedges iscontemplated as being controlled either by means of thread lengths inwhich case the run-out of the threads would bottom out on the respectivewedges or by means of dedicated ridges (e. g. 510 and 515)circumferentially disposed around the actuator and configured to bottomout on the respective wedges thereby limiting translation of theactuator. It should be understood that although the various alternativegeometries of the actuators are presented here as discrete embodiments,these alternative embodiments have optional features which may besubstituted or mixed/matched with any other embodiment in thespecification. It should also be understood that substituting any of theaforementioned optional alternative features in the actuator componentwill necessitate the mating components (such as the wedges, the ramps orany auxiliary instrumentation intended to engage the actuator 500) touse the inverse or complementary geometry of those features for properengagement and that the shape of that inverse geometry would followinevitably from the optional alternative feature geometry describedabove.

With respect to FIG. 22, the retaining pin 600 comprises a first end604, a second end 602, and a cylindrical surface 606 connecting the ends604 and 602, whereas the cylindrical surface 606 may have any diameterand any length suitable for a particular application, mating feature orcomponent. With respect to FIG. 23, the retaining set screw 700comprises a first end 704, a second end 702, and a threaded surface 705connecting the ends 704 and 702. The retaining set screw 700 furthercomprises a drive feature proximate the first end 704 and a cylindricalprotrusion 710 extending from the second end 702. With respect to FIG.24, the retaining c-clip 720 comprises an inner diameter 724, an outerdiameter 722, and a split 725 interrupting both the inner diameter 722and the outer diameter 724.

Referring further to FIGS. 26A-26B, in an exemplary embodiment, theproximal wedge 550 comprises a first end 562, a second end 560, an uppersurface 590 connecting the first end 562 and the second end 560, and alower surface 552 connecting the first end 562 and the second end 560.The proximal wedge further comprises a first ramped surface 580 and asecond ramped surface 582 located proximate the second end 560. Thefirst ramped surface 580 includes a first projection 564 extending fromthe first ramped surface 580 towards a surface 565 and having agenerally trapezoidal cross-section. The second ramped surface 582includes a second projection 566 extending from the second rampedsurface 582 toward a surface 567 and having a generally trapezoidalcross-section. Optionally, in any embodiment, the first projection 564includes a protuberance 574 and the second projection 566 includes aprotuberance 575. The projections 564 and 566 are contemplated to beconfigured to slidably engage the tapered channel 328 of the ramp 300 inthe endplates in such a way that the ramp 300 only translates relativeto the proximal wedge 550 in one dimension—back and forth in either in astraight or a curved line (Optionally, in any embodiment, rotation inone plane may also be allowed between the ramps and the wedge 550).

Optionally, in any embodiment, the protuberances 574 and 575 areconfigured to engage the groove 322 on the ramp 300 in the endplates andlimit the extent of translation between the ramp 300 and the wedge 550by making contact with the surface 324 at the limit of allowable travel.Optionally, in any embodiment, the upper surface 590 further includes aprojection 554 extending from the upper surface 590. The projection 554includes a channel 599 extending through the first end 562 but notthrough the second end 560. It should be understood that the channel 599is intended as a mating feature for auxiliary instrumentation used inintroduction, expansion of the device 1000 and/or graft delivery intothe device 1000 and may be configured, shaped and located in other waysso long as it is accessible from the first end 562. The proximal wedge550 further comprises a central aperture 568 (e. g. as shown in FIG.19), and side apertures 570 and 572 (e. g. as shown in FIG. 26B).Optionally, in any embodiment, the central aperture 568 includes anundercut 571 and both of the side-apertures 570 and 572 are threaded.The central aperture 568 is configured to engage and retain the actuator500 by means of the retaining set screw 700 engaged in a threaded hole586 and extending into the groove 514 of the actuator 500 and/or theretaining pin 600 engaged in a bore 584 and extending into the groove514 of the actuator 500 or the retaining c-clip 720 (see FIG. 24)engaged simultaneously in the undercut 571 and the groove 514 of theactuator 500 (shown in FIG. 25) or any other retaining mechanismallowing the actuator 500 to rotate inside the central aperture 568, butsubstantially preventing the actuator 500 from translating along theaxis of the central aperture 568.

It should be understood that although in the illustrative embodiment,the first projection 564 and the second projection 566 have trapezoidalcross-sections, or a cross section including but not limited to T-shapedcross-section, Y-Shaped cross-section (not shown), or generally anycross-section that preferably results in the projections 564 and 566being narrower at the ramped surfaces 580 and 582 than they are at thesurfaces 565 and 567. Similarly, any embodiment may optionally have thecross-sections described above. FIG. 27A shows an embodiment with theprojections 564 and 566 having T-shaped cross-sections, which may beparticularly preferable due to manufacturability and performanceconsiderations.

Side apertures 570 and 572 are intended as a mating features forauxiliary instrumentation used in introduction and/or expansion of thedevice 1000 and/or graft delivery into the device 1000 and may beconfigured, shaped and located in other ways so long as they areaccessible from the first end 562. As an example, there may be one ortwo side apertures, one, both or none of the side apertures may bethreaded, one or both of the side apertures may be non-circular.Additionally, the central aperture 568 is intended to mate with theactuator and may or may not be in the geometric center of the proximalwedge 550, and may or may not be threaded. As an example, FIG. 27B showsan exemplary proximal wedge 550 in which the central aperture isthreaded with a left-handed thread (but may in other embodiments bethreaded with a right-handed thread), one of the side apertures isthreaded and one of the side apertures has a generally rectangular orpreferably, a generally square shape, which is seen as advantageous forgraft delivery into the fusion device 1000 because it may provide agreater cross-sectional area for graft material to travel through ascompared to a circular opening of similar external dimensions. Otheroptional instrument attachment features are also contemplated includingbut not limited to embodiments of the proximal wedge 550 shown in FIGS.27B, 27C, and 27D. For example, an embodiment shown in FIG. 27B does notinclude the projection 554 and instead includes a projection 587 and aprojection 588 extending from the upper surface and forming a channel591 and a projection 589 and a projection 590 extending from the lowersurface 552 and forming a channel 592. FIG. 27C shows the embodimentfrom FIG. 27B which includes a groove 592 extending from the projection587 to the projection 589. Optionally, in any embodiment, another groove(not shown) of similar dimensions may extend from the projection 589 tothe projection 590. It is further contemplated that these grooves wouldserve as engagement features for auxiliary instrumentation. Theembodiment of FIG. 27C further includes both side apertures beingcircular and threaded and the central aperture being unthreaded. FIG.27D shows the embodiment from FIG. 27C which further includes steppedrecesses 593 and 594 on the sides of the proximal wedge 550 with thedeeper portions of the stepped recesses 593 and 594 located proximatethe second end 560. Optionally, in any embodiment, the stepped recesses593 and 594 would serve as engagement features for auxiliaryinstrumentation. The embodiment of FIG. 27D further includes one of theside apertures being circular and threaded, one aperture being generallyrectangular or preferably, generally square in shape and the centralaperture being unthreaded. Auxiliary instrumentation is discussed indetail below. Optionally, in any embodiment, the slopes of the rampedsurfaces 580 and 582 (and the slopes of the ramped surfaces 680 and 682discussed below) are equal or differ from each other. Since the branchesof the ramped surfaces 580, 582 (as well as 680, 682 discussed below) ofthe wedges are intended to mate with the ramped surfaces 320 of theramps 300, 350, 400, 450, the effects of varying their slopes is thesame as discussed above for the ramped surfaces 320 in the ramp 300. Itshould be understood that although the various alternative geometries ofthe proximal wedges are presented here as discrete embodiments, thesealternative embodiments have optional features which may be substitutedor mixed/matched with any other embodiment in the specification. Itshould also be understood that substituting any of the aforementionedoptional alternative features in the proximal wedge component willnecessitate the mating components (e. g. the endplates, the ramps, theactuator and the distal wedge) to use the inverse or complementarygeometry to those features for proper engagement and that the shape ofthat inverse geometry would follow inevitably from the optionalalternative feature geometry described above.

Turning now to FIGS. 28A and 28B, in an exemplary embodiment, the distalwedge 650 comprises a first end 662, a second end 660, an upper surface690 connecting the first end 662 and the second end 660, and a lowersurface 652 connecting the first end 662 and the second end 660. Theproximal wedge further comprises a planar first ramped surface 680 and aplanar second ramped surface 682 located proximate the second end 660.The first ramped surface 680 includes a first projection 664 extendingfrom the first ramped surface 680 toward a surface 665 and having agenerally trapezoidal cross-section. The second ramped surface 682includes a second projection 666 extending from the second rampedsurface 682 toward a surface 667 and having a generally trapezoidalcross-section. Optionally, in any embodiment, the first projection 664includes a protuberance 674 and the second projection 666 includes aprotuberance 675. The projections 664 and 666 are contemplated to beconfigured to slidably engage the tapered channel 328 of the ramp 300 inthe end plates in such a way that the ramp 300 only translates relativeto the proximal wedge 650 in one dimension—back and forth in either in astraight or a curved line. Optionally, in any embodiment, theprotuberances 674 and 675 are configured to engage the groove 322 on theramp 300 and limit the extent of translation between the ramp 300 andthe wedge 650 by making contact with the surface 324 at the limit ofallowable travel. Optionally, in any embodiment, in an embodiment, theupper surface 690 further includes a projection 654 extending from theupper surface 690 and a projection 655 extending from the lower surface652. The projections 654 and 655 further include chamfers 688 and 689configured to facilitate introduction of the device 1000 between andinitial distraction of the adjacent vertebrae 2 and 4. The distal wedge650 further comprises a central aperture 668, and side apertures 670 and672. The central aperture 668 is fully threaded and both of theside-apertures 670 and 672 are threaded. The central aperture 668 isconfigured to engage the actuator 500. Side apertures are intended as amating features for auxiliary instrumentation used in introductionand/or expansion of the device 1000 and/or graft delivery into thedevice 1000 and may be configured, shaped and located in other ways.Optionally, in any embodiment, there may be one or two side apertures,one, both or none of the side apertures 670 and 672 may be threaded andone or both of the side apertures 670 and 672 may be non-circular. FIG.29A shows, as an example, an exemplary distal wedge 650 which does notinclude the side apertures. It should be understood that although in theillustrative embodiment, the first projection 664 and the secondprojection 666 have trapezoidal cross-sections, they or any otherembodiment disclosed herein may optionally have but are not limited tothe following, T-shaped cross-section, Y-Shaped cross-section, L-shapedcross-section or generally any cross-section that preferably results inthe projections 664 and 666 being narrower at the ramped surfaces 680and 682 than they are at the surfaces 665 and 667. FIG. 29B shows anexemplary distal wedge 650 with the projections 664 and 666 havingT-shaped cross-sections, which may be particularly preferable due tomanufacturability and performance considerations. Optionally, in anyembodiment, the slopes of the ramped surfaces 580 and 582, and theslopes of the ramped surfaces 680 and 682 are equal or differ from eachother. Since the branches of the ramped surfaces 580, 582, 680, 682 ofthe wedges are intended to mate with the ramped surfaces 320 of theramps 300, 350, 400, 450, the effects of varying their slopes is thesame as discussed above for the ramped surfaces 320 in the ramp 300. Itshould be understood that although the various alternative geometries ofthe distal wedges are presented here as discrete embodiments, thesealternative embodiments have optional features which may be substitutedor mixed/matched with any other embodiment in the specification. Itshould also be understood that substituting any of the aforementionedoptional alternative features in the distal wedge component willnecessitate the mating components (e. g. the endplates, the ramps, theactuator and the proximal wedge) to use the inverse or complementarygeometry to those features for proper engagement and that the shape ofthat inverse geometry would follow inevitably from the optionalalternative feature geometry described above.

Turning now to method of implantation of the fusion device 1000 betweentwo adjacent vertebral bodies 2 and 4. FIGS. 30, 31, and 32 show anembodiment of an inserter 800 configured to be reversibly attached tothe fusion device 1000, allow the fusion device 1000 to be implantedbetween the adjacent vertebral bodies 2 and 4 and facilitate graftdelivery into the fusion device 1000. Optionally, in any embodiment, theinserter 800 comprises an elongate main body 820 of a generallyrectangular shape but may be other shapes in other embodiment, mostpreferably having a cross-section that is substantially the same as thetransverse cross-section of the fusion device 1000 in the initialcollapsed state. The inserter 800 further comprises a threaded shaft 840slidably disposed in the main body. The main body 820 further comprisesa distal end configured to mate with the proximal wedge 550 of thefusion device 1000 and includes three apertures running throughout theentire length of the main body 820. The first aperture 821 allows thethreaded shaft 840 to access one of the threaded side-apertures of theproximal wedge 550 allowing the reversible attachment of the inserter800 to the fusion device 1000 by means of threading the threaded shaft840 into the proximal wedge 550. The second aperture 822 allows anexpansion driver 870 to access the drive feature 512 of the actuator500. The expansion driver 870 is shown in FIG. 33 and comprises a distalend including a drive feature 877 compatible with the drive feature 512of the actuator 500 and a proximal end including an attachment feature875 for a torque handle, a torque-limiting handle or a torque indicatinghandle used to actuate the actuator 500 and achieve expansion of thefusion device 1000. The third aperture 823 allows access to a sideaperture of the proximal wedge 550 for the purpose of delivering atherapeutic agent such as bone graft or bone growth inducing materialinto the fusion device 1000 post expansion. The distal end of the mainbody 820 further comprises flat planar plates forming ledges 825 and 827intended to prevent height expansion of the fusion device 1000 until thewidth expansion is substantially complete. Once the inserter 800 isattached to the fusion device 1000 by means of threading the threadedshaft 840 into the proximal wedge 550 (see FIG. 34), the fusion device1000 are implanted between the adjacent vertebral bodies 2 and 4 (seeFIG. 35). Once the initial implanted position of the fusion device 1000is found to be satisfactory, the expansion driver 870 is slidablyintroduced into the second aperture 822 in the inserter 800 and thedrive feature 877 is engaged with the drive feature 512 of the actuator500 (see FIG. 36). Applying torque to the expansion driver 870 nowresults in expansion of the fusion device 1000. FIG. 37 shows theinserter 800 attached to the fusion device 1000 in fully collapsed stateand the ledge 825 partially covering the endplates thereby preventingheight expansion but allowing the width expansion of the fusion device1000. The ledge 825 in FIG. 37 is shown covering a portion of theendplates and preventing height expansion of the fusion device 1000.FIG. 38 shows the inserter 800 attached to the fusion device 1000 in astate of partial width expansion and the ledge 825 partially coveringthe endplates thereby preventing height expansion but allowing furtherwidth expansion of the fusion device 1000. FIG. 39 shows the inserter800 attached to the fusion device 1000 in a state of full widthexpansion and the ledge 825 no longer covering the endplates therebyallowing height expansion of the fusion device 1000. FIG. 40 shows theinserter 800 attached to the fusion device 1000 in a state of full widthand height expansion. Bone graft or bone growth inducing material (graftmaterial) is then introduced, delivered or injected into the fusiondevice 1000 through the third aperture 823 of the inserter 800.Optionally, in any embodiment, graft material may be pre-packed into thethird aperture 823 prior to attaching the inserter 800 and tampedthrough the third aperture 823 and into the fusion device 1000 using anelongated tamp (not shown) configured to fit through the third aperture823 once the fusion device 1000 is implanted and expanded. It is furthercontemplated that graft material may be delivered into the proximalopening of the third aperture 823 by means including but not limited toa syringe, a funnel, a thread-actuated graft delivery device or agrip-operated graft delivery device after the device 1000 has beenexpanded. The elongated tamp is then used to push any graft materialremaining inside the third aperture 823 into the fusion device 1000. Itis further contemplated that graft material are introduced into thefusion device 1000 after it has been expanded and after the inserterinstrument has been detached, the graft are introduced through any ofthe available apertures in the proximal wedge 550 or through the gapsbetween the first vertebral endplate 6 and the proximal wedge 550 orthrough the gap between the second vertebral endplate 8 and the proximalwedge 550 or both at the same time. FIG. 41 shows the fusion device 1000in fully expanded state filled with bone graft material and stillattached to the inserter 800. FIG. 42 shows the fusion device 1000between the two adjacent vertebral bodies 2 and 4 in fully expandedstate filled with bone graft and detached from the inserter 800. Theimplantation of the fusion device 1000 is then complete and the surgicalwound may then be closed.

FIG. 43 shows an exemplary inserter instrument. An inserter 900comprises a main shaft 955, a sleeve 930, a wheel 945, a handle 915, andpins 970 and 971. The main shaft 955 further comprises a distal endconfigured to mate with the proximal wedge 550 of the fusion device 1000and an external thread located proximate the proximal end. A detailedsection view of the threaded articulation of the inserter is seen inFIG. 44. As shown in FIGS. 45 and 46, the main shaft further includesthree apertures running throughout the entire length of the main shaft955. The second aperture 961 allows an expansion driver 870 to accessthe drive feature 512 of the actuator 500. The first aperture 961 andthe third aperture 963 allow access to the side apertures of theproximal wedge 550 for the purpose of delivering bone graft or bonegrowth inducing material into the fusion device 1000 post expansion. Thedistal end of the main shaft 955 further comprises a first tang 956including a distal protrusion 964 and a second tang 957 including adistal protrusion 965. The tangs 956 and 957 are partially separatedfrom the main bulk of the main shaft 955 by the slits 958 and 959, whichgive the tangs flexibility. Distal ends of the tangs are configured toengage mating features of an exemplary proximal wedge 550; thisarticulation is shown in a section view in FIG. 47. The sleeve 930 isconfigured to slide over the main shaft 955 and are advanced distally orproximally along the main shaft 955 by means of turning the wheel 945which is threadably engaged with the main shaft 955 and rotationallyengaged with the sleeve 930 by means of the pins 970 and 971, whichresults in an articulation whereby the wheel 945 rotates relative to thesleeve 930 but not translate relative to it. The handle 915 is rigidlyattached to the proximal end of the main shaft 955. When the sleeve 930is in its proximal-most position (shown in FIG. 48), the tangs 956 and957 are allowed to elastically deform away from each other to engage themating features on the proximal wedge 550 of the fusion device 1000, andwhen the sleeve 930 is in its distal-most position (shown in FIG. 49),it prevents the tangs 956 and 957 from elastically deforming away fromeach other, resulting in a positive engagement between the proximalwedge 550 of the fusion device 1000 and the inserter 900. Furthermore,in its distal-most state the sleeve 930 and specifically its distal endcarries out the same function in the inserter 900 as the ledges 825 and827 do in the inserter 800, this function being preventing the fusiondevice 1000 from expanding in height until the width expansion has beensubstantially complete. Once the inserter 900 is attached to the fusiondevice 1000, the fusion device 1000 is implanted between the adjacentvertebral bodies 2 and 4. Once the initial implanted position of thefusion device 1000 is found to be satisfactory, the expansion driver 870is introduced into the second aperture 962 in the inserter 900 and thedrive feature 877 is engaged with the drive feature 512 of the actuator500 (see FIG. 50). Applying torque to the expansion driver 870 nowresults in expansion of the fusion device 1000 first in width (see FIG.51) and then in both width and height (see FIG. 52). The delivery of thebone graft material through the inserter 900 and into the fusion device1000 may now be accomplished through one or both of the apertures 961and 963 in the way discussed above. FIG. 53 shows the fusion device 1000in fully expanded state filled with bone graft material and stillattached to the inserter 900. The inserter 900 may then be detached fromthe fusion device 1000, the implantation of the fusion device 1000 isthen complete, and the surgical wound may then be closed.

Second Expandable Fusion Device

Turning now to FIGS. 54A-54C, which show an exemplary second expandablefusion device 1000 a. FIG. 54A shows an exemplary second expandablefusion device 1000 a in a fully collapsed state, FIG. 54B shows anexemplary second expandable fusion device 1000 a in a fully expandedstate and FIG. 54C shows an exploded view of an exemplary secondexpandable fusion device 1000 a. Optionally, in any embodiment, thesecond expandable fusion device 1000 a comprises an embodiment 300 a ofthe first ramp 300 (as well as the ramps 350 a, 400 a and 450 a, whichare all identical in this embodiment, and the ramp 400 a is used toindicate the reference numbers for the ramp 300 a in FIG. 54C) is thesame as the exemplary embodiment of the first ramp 300 with thefollowing exceptions: the outer surface 327 includes ramped slot 335 athat is parallel to the ramped surfaces of the branch 323, the branches321 and 323 have generally C-shaped cross-sections, the surfaces 329 and330 include protrusions 337 a and 338 a, the channel 328 has a generallyT-shaped cross-section and does not include the groove 322 present inpreviously discussed embodiments of the ramp 300.

The second expandable fusion device 1000 a further comprises anembodiment 100 a of the first endplate 100 (as well as the endplates 150a, 200 a and 250 a, which are all identical in this embodiment, but mayneed to be suitably aligned in order to be assembled into thearrangement of the second expandable fusion device 1000 a) in which theramped slots 107 and 109 have C-shaped cross-sections configured to matewith the ramp 300 a, the top surface 132 includes a protrusion 145 aproximate the slot 109 and a recess 146 a proximate the ramped slot 107,whereas the protrusion 145 a and the recess 146 a have complementaryshapes so that when two endplates are suitably rotated, the protrusion145 a of one nests in the recess 146 a of the other allowing the bottomsurface of the top endplate and the top surface of the bottom endplateto touch. The outward facing surface of the protrusion 145 a furtherincludes a divot 147 a (shown in FIG. 54C on the endplate 200 a) that isgenerally aligned with the long axis of the ramped slots 335 a of theramp 300 a when assembled but doesn't go all the way through to theother side of the endplate. Divot 147 a may have spherical, cylindrical(as shown) or any other shape. The purpose of the divot is to create anarea of thinned material between the bottom of the divot and the inwardsurface of the ramped slot 109, which allows to deform (peen) the bottomof the divot and create protruding dimple 148 a on the inward facingsurface of slot 109 of the endplate. The peening step is performed asthe last step in assembly process when the components are assembled andare in a fully collapsed state and is performed by means of a punch or apointed or rounded tool applying load to the bottom surface of the divotby means of impaction, pressing, or other means. As described above, thepeening produces the dimple 148 a on the inward facing surfaces of theendplates, which in the assembled device state—lines up with and engagesthe ramped recesses of the ramps, capturing them and preventingdis-assembly of the second expandable fusion device 1000 a byhyper-expansion. Optionally, in any embodiment, the divots are replacedwith thru-openings in the endplates and the function of the peeneddimples are performed by pins pressed through the end endplate openingsand engaging the ramped slots of the ramps. The endplate 100 a does notinclude tapered grooves 122, 118, 124 and 120 present in previouslydiscussed embodiments of the endplate 100, but instead includes rampedsurfaces 121 a and 123 a (shown in FIG. 54C on the endplate 200 a),which perform generally the same function as the grooves 122, 118, 124and 120, which is to prevent height expansion from taking place untilthe device is sufficiently expanded in width. This is accomplishedthrough the ramped surfaces 121 a and 123 a being in contact with matingramped surfaces of the wedges throughout most of the width expansionprocess and while they are in contact with the wedges, the ramps on theopposing sides of each endplate are only able to move along thedirection of the ramped surfaces of the wedges and the ramped surfaces121 a and 123 a, while remaining static relative to one another, whereasto achieve height expansion the opposing ramps need to be able to movetoward each other along the long axis of the device. Once the widthexpansion is substantially completed and once the ramped surfaces 121 aand 123 a no longer contact the wedges, the ramps are allowed to movetoward each other resulting in height expansion. The top surface 132further includes a protrusion 115 a proximate the ramped slot 107 andthe inward surface 130 includes a recess 117 a proximate the slot 109,whereas the protrusion 115 a and the recess 117 a have complementaryshapes so that when two endplates are suitably rotated, the protrusion115 a of one nests in the recess 117 a of the other allowing theopposing top and bottom surfaces of the two endplates to touch.Protrusion 115 a is configured to mate with the ramp 300 a as anextension of the ramped surfaces of the ramped slot 107. The purpose ofthe protrusion 115 a is to increase device stability at the upper limitsof allowed height expansion by maintaining a large contact area betweenthe ramp and the endplate. The endplate 100 a further includes anopening 119 a extending from the inner surface to the outer surface.This feature is optional and is contemplated to allow graft material toexit the interior of the device and fill the space surrounding it. Theendplate 100 a further includes a relief 149 a whose axis issubstantially parallel to the long axis. The relief 149 a is configuredto mate with the actuator 500 a and allow the endplates to be in closerproximity to each other than would otherwise be possible without therelief 149 a.

The second expandable fusion device 1000 a further comprises anembodiment 500 a of the actuator 500. The actuator 500 a comprises aproximal end 504 a, a distal end 502 a and a cylindrical surface 506 aconnecting the proximal end 504 a and the distal end 502 a. Optionally,in any embodiment, the actuator 500 a further comprises a drive feature512 a on the proximal end 504 a, a thread 517 a proximate the proximalend 504 a, and a thread 508 a proximate the distal end 502 a. The thread508 a is comprised of a helical groove of opposite direction to that ofthe thread 508 (e. g. if the thread 508 a is right-handed, then thethread 517 a is left-handed or vice versa). This embodiment furtherincludes a second drive feature on the distal end (not shown). Thissecond drive feature is deemed useful in the event of a revision surgerywhere the revision approach is not the same as the approach used duringthe original surgery.

The second expandable fusion device 1000 a further comprises anembodiment 550 a of the proximal wedge 550. The proximal wedge 550 a isshown in front and rear perspective views in FIG. 55A and FIG. 55Brespectively. The proximal wedge 550 a comprises a first end 562 a, asecond end 560 a, an upper surface 590 a connecting the first end 562 aand the second end 560 a and a lower surface 552 connecting the firstend 562 a and the second end 560 a. The proximal wedge further comprisesa first ramped surface 580 a and a second ramped surface 582 a locatedproximate the second end 560 a. The first ramped surface 580 a includesa first ramped recessed track 591 a proximate the upper surface and asecond ramped recessed track 592 a proximate the lower surface. Thefirst ramped surface 580 a further includes a projection 564 a extendingfrom the first ramped surface 580 a towards a surface 565 a and having agenerally T-shaped cross-section. The projection 564 a results in theramped surface 580 a to be split into an upper portion and a lowerportion. The second ramped surface 582 a includes a first rampedrecessed track 593 a proximate the upper surface and a second rampedrecessed track 594 a proximate the lower surface. The second rampedsurface 582 includes a projection 566 extending from the second rampedsurface 582 a toward a surface 567 and having a generally T-shapedcross-section. The projection 566 a results in the ramped surface 582 ato be split into an upper portion and a lower portion. The rampedrecessed tracks 591 a, 592 a, 593 a, and 594 a do not break through theside surfaces of the wedge 550 a and function to limit the travel of theramps relative to the proximal wedge by functioning as a depth stop forthe protrusions 337 a and 338 a of the ramp 300 a to bottom out on. Theupper surface 590 a further includes a projection 554 a extending fromthe upper surface 590 a. The lower surface 552 a further includes aprojection 555 extending from the lower surface 552 a. The projections554 a and 555 a include channels 599 a and 598 a extending through thefirst end 562 a and the second end 560 a. It should be understood thatthe channels 599 a and 598 a are intended as a mating features forauxiliary instrumentation used in introduction, expansion of the secondexpandable fusion device 1000 a and/or graft delivery into the secondexpandable fusion device 1000 a and may be configured, shaped andlocated in other ways so long as they are accessible from the first end562 a. The proximal wedge 550 a further comprises a threaded centralaperture 568 a and generally rectangular apertures 570 a and 572 a whichbreak through the respective sides of the proximal wedge 550 a. Theproximal wedge 550 a further includes a partial bore 597 a extendingfrom the first end 562 a to some depth toward, but not all the way tothe second end 560 a and about centering on the major diameter of thethreaded central aperture 568 a interrupting its threads. The partialbore 597 a allows to access the proximal end of the threaded actuatorafter the device has been expanded and to deform the first threads on itusing a punch, awl, or an automatic punch tool. This is done to preventor reduce the chances of the actuator unthreading post-operativelyresulting in the device losing height.

The second expandable fusion device 1000 a further comprises anembodiment 650 a of the distal wedge 650 (best seen in exploded view inFIG. 54C) n this embodiment, the proximal wedge 650 a is identical tothe proximal wedge 550 a with the exception that the distal wedge 650 aincludes a central aperture that is threaded in the direction oppositeto that of the proximal wedge. For example, if the central aperture ofthe proximal wedge 550 a has a left-handed thread, then the centralaperture of the distal wedge 650 a has a right-handed thread.Optionally, in any embodiment, having all the insertion features presenton the proximal wedge also being present on the distal wedge along withthe actuator having a second drive feature on the distal end (asdiscussed above) is useful in the event of a revision surgery where therevision approach is not the same as the approach used during theoriginal surgery. Optionally, in any embodiment, the distal wedge mayhave a more bulleted distal end to facilitate initial implantation.

It should also be understood that although the various alternativegeometries of the various components are presented here as discreteembodiments, these alternative embodiments have optional features whichmay be substituted or mixed/matched with any other embodiment in thespecification. It should also be understood that substituting any of theaforementioned optional alternative features in any of the componentsmay or will necessitate the mating components to use the inverse orcomplementary geometry of those features for proper engagement and thatthe shape of that inverse or complementary geometry would followinevitably from the optional alternative feature geometry describedabove and from the detailed description of the embodiments described asutilizing that geometry. As an example, the device second expandablefusion device utilizes some or any of the actuator embodiments, heightand width expansion features, configurations and embodiments as well asthe endplate stabilization features and embodiments described here.

Third Expandable Fusion Device

Turning now to FIGS. 56A-56C, which show an exemplary third expandablefusion device 1000 b. FIG. 56A shows an exemplary third expandablefusion device 1000 b in a fully collapsed state, FIG. 56B shows anexemplary third expandable fusion device 1000 b in a fully expandedstate and FIG. 56C shows an exploded view of an exemplary thirdexpandable fusion device 1000 b. The third expandable fusion device 1000b has similar functionality as the previously discussed embodiments inthat it is configured transition from the initial collapsed state (shownin FIG. 56A) to the final expanded state (shown in FIG. 56B), but theexpansion is accomplished using a modified mechanism where ramped slotsof the ramp 300 b are configured to accept pins 600 inserted through themating openings in the endplates 100 b. Since the endplates 100 bcontain no ramped surfaces, the height expansion is accomplished by thepins 600 traveling along the ramped slots and by the various curvedsurfaces of the endplates making tangent contact with the rampedsurfaces of the ramps. Disassembly by hyper-expansion is prevented bymeans of the pins 600 bottoming out in the ramped slots of the ramps 300b at the limit of allowed travel. The third expandable fusion device1000 b comprises an embodiment 300 b of the first ramp 300 (as well asthe ramps 350, 400 and 450, which are all identical in this embodiment)shown in complementary views in FIGS. 57A and 57B has a first end 301 band a second end 303 b. The first ramp 300 b further comprises an innersurface 305 b connecting the first end 301 b and the second end 303 b,and an outer surface 307 b (best seen in FIG. 57B) connecting the firstend 301 b and the second end 303 b. The first ramp 300 b furthercomprises an upper surface 309 b connecting the first end 301 b and thesecond end 303 b, and a lower surface 311 b connecting the first end 301b and the second end 303 b, the two surfaces 309 b and 311 b beingpreferably parallel to each other. The first ramp 300 b furthercomprises a protuberance 315 b further comprising an upper branch 321 bextending preferably past the outer surface 307 b and the upper surface309 b, and a lower branch 323 b extending preferably past the outersurface 307 b and the lower surface 311 b. The upper branch 321 bcomprises an upper end surface 341 b, a first ramped surface 302 b andpreferably a second ramped surface 310 b. The lower branch 323 bcomprises a lower end surface 343 b, a first ramped surface 304 b andpreferably a second ramped surface 312 b. The inner surface 305 bincludes a projection 319 b forming a ramped surface 320 b. Theprojection 319 b includes a first branch 314 b and a second branch 316b. The first branch 314 b extends from the ramped surface 320 b to asurface 329 b and the second branch 316 b extends from the rampedsurface 320 b to a surface 330 b. The ramped surface 320 b and thebranches 314 b and 316 b form a channel 328 b having a generallyT-shaped cross-section, which is formed due to the branches 314 b and316 b including respective projections extending along and beingparallel to the ramped surfaces 329 b and 330 b respectively andextending toward each other The first branch 314 b further includes aprojection 348 b and the second branch 316 b further includes aprojection 349 b. The projection 319 b further includes a relief 306 bwhose axis is substantially parallel to the long axis. The relief 306 bis configured to mate with the actuator 500 a and allow the ramps to bein closer proximity to each other than would otherwise be possiblewithout the relief 306 b. The relief 306 b has any cross-sectionsuitable to accomplish the function described above, for example agenerally rectilinear cross-section. The ramp 300 b further comprises afirst ramped slot 337 b recessed into the inner surface 305 b andextending from midplane of the ramp 300 b toward the upper branch 321 bbut not breaking through the upper end surface 341 b, and a secondramped slot 338 b recessed into the outer surface 327 b and extendingfrom the midplane of the ramp 300 b toward the branch 323 b, but notbreaking through the lower end surface 343 b. The ramp 300 b furthercomprises a first ramped relief 341 b extending from the midplane of theramp 300 b and toward the branch 321 b and disposed between the innersurface 305 b and the inner margin of the projection 319 b and a secondramped relief 342 b extending from the midplane of the ramp 300 b andtoward the branch 323 b and disposed between the inner surface 305 b andthe inner margin of the projection 319 b. The slope of the rampedreliefs may or may not be parallel to the respective ramped slots andthe purpose of the ramped reliefs is to clear parts of the endplateduring height expansion.

The third expandable fusion device 1000 b further comprises anembodiment 100 b (best seen in FIG. 58) of the first endplate 100 (aswell as the endplates 150, 200 and 250, which are all identical in thisembodiment) which comprises a first end 102 b and a second end 104 b.The first endplate 100 b further comprises an upper surface 134 bconnecting the first end 102 b and the second end 104 b, and a lowersurface 132 b connecting the first end 102 b and the second end 104 b.The first endplate 100 b further comprises a first elongated opening 107b proximate the first end 102 b and a second elongated opening 109 bproximate the second end 104 b. The elongated openings 107 b and 109 bextend from the lower surface 132 b through the upper surface 140 b inthe direction perpendicular to the long axis. The first endplate 100 bfurther comprises a first elongated recess 110 b extending from thefirst end 102 b and past the first elongated opening 107 b and a secondelongated recess 112 b extending from the second end 104 b and past thesecond elongated opening 109 b. The elongated recesses 110 b and 112 bextend from the bottom surface 132 b toward but not through the uppersurface 140 b in the direction perpendicular to the long axis andforming a first inward face 114 b and a second inward face 116 brespectively.

The bottom surface 132 b includes a first protrusion 145 b proximate theopening 107 b, a second protrusion 145 b 1 proximate the opening 109 b,a first recess 146 b proximate the first opening 107 b and a secondrecess 146 b 1 proximate the second opening 109 b. Whereas theprotrusions 145 b and 145 b 1 and the recesses 146 b and 146 b 1 havecomplementary shapes so that when two endplates are collapsed againsteach other, the protrusion 145 b of one nests in the recess 146 b 1 ofthe other and the protrusion 145 b 1 of one nests in the recess 146 b ofthe other, while allowing the respective top and bottom surfaces of thetwo endplates to touch and the inner surfaces 130 b of the two endplatesto be aligned. The centers of the protrusions are configured togenerally align with the ramped slots of the ramp 300 b when assembled.The protrusions 145 b and 145 b 1 further include thru openings 147 band 147 b 1 respectively, configured to accept pins that would engagethe ramped slots of the ramp 300 b. The inner surface 130 b furtherincludes a relief 149 b whose axis is substantially parallel to the longaxis. The relief 149 a is configured to mate with the actuator 500 b andallow the endplates to be in closer proximity to each other than wouldotherwise be possible without the relief 149 b. The inner surface 130 bfurther includes an opening 119 b extending from inward facing surfaceto the outward facing surface. This feature is optional and iscontemplated to allow graft material to exit the interior of the deviceand fill the space surrounding it. The first inward face 114 b and thesecond inward face 116 b further include a first protrusion 118 b and asecond protrusion 120 b respectively. The protrusions are rounded on thesurfaces facing each other. The rounded sections of the protrusions 114b and 116 b are configured to make tangent contact with the rampedsurfaces 310 b and 312 b of the ramp 300 b to increase the contact areabetween the endplates and the ramps. The corners formed by at least thefirst end 102 b and the inward surface 130 b and by the second end 104 band the inward surface 130 b include rounded surfaces 121 b and 123 brespectively. The purpose of these rounded surfaces is to help preventheight expansion from taking place until the device is sufficientlyexpanded in width. This is accomplished through the rounded surfaces 121b and 123 b being in tangent contact with mating ramped surfaces of thewedges throughout most of the width expansion process and while they arein tangent contact with the wedges, the ramps 300 b on the opposingsides of each endplate 100 b are only able to move along the directionof the ramped surfaces of the wedges 550 b and 650 b as these rampedsurfaces make tangent contact with rounded surfaces 121 a and 123 a,while the ramps 300 b remain static relative to one another, whereas toachieve height expansion the opposing ramps need to be able to movetoward each other along the long axis of the device. Once the widthexpansion is substantially completed and once the rounded surfaces 121 aand 123 a no longer tangentially contact the wedges, the ramps areallowed to move toward each other resulting in height expansion. Theupper surface 134 b includes texturing 140 b to aid in gripping theadjacent vertebral bodies. Although In the illustrated embodiment, thetexturing 140 b comprises series of parallel grooves runningtransversely to the long axis of the endplate 100 b, including but isnot limited to teeth, ridges, areas of high surface roughness, metallicor ceramic coatings with relatively high surface roughness, frictionincreasing elements, keels, spikes, or gripping or purchasingprojections. Optionally, in any embodiment, one or more of the endplatesmay be shorter, longer, narrower, or wider than others.

The third expandable fusion device 1000 b further comprises the proximalwedge 550 a, the distal wedge 650 a, the actuator 500 a and pins 600.

It should also be understood that although the various alternativegeometries of the various components are presented here as discreteembodiments, these alternative embodiments have optional features whichmay be substituted or mixed/matched with any other embodiment in thespecification. It should also be understood that substituting any of theaforementioned optional alternative features in any of the componentsmay or will necessitate the mating components to use the inverse orcomplementary geometry of those features for proper engagement and thatthe shape of that inverse or complementary geometry would followinevitably from the optional alternative feature geometry describedabove and from the detailed description of the embodiments described asutilizing that geometry. As an example, the third expandable fusiondevice 1000 b may utilize some or any of the actuator embodiments,height and width expansion features, configurations and embodiments aswell as the endplate stabilization features and embodiments describedhere.

Fourth Expandable Fusion Device

Turning now to FIGS. 59A-59C, which show an exemplary fourth expandablefusion device 1000 c. FIG. 59A shows an exemplary fourth expandablefusion device 1000 c in a fully collapsed state, FIG. 59B shows anexemplary fourth expandable fusion device 1000 c in a fully expandedstate and FIG. 59C shows a top view of an exemplary fourth expandablefusion device 1000 b. The fourth expandable fusion device 1000 c isidentical to the previously described third expandable fusion device1000 b except that in the third expandable fusion device 1000 c, theendplates include nested interlocking stabilization features (best seenin FIG. 59D) allowing to improve stability, ensure proper alignment andreduce “slop” between top and bottom end-plates on either side of thedevice and facilitate even device expansion. Opposing endplates (FIG.59D for example shows the opposing endplates 100 c and 150 c) on top andbottom of the fourth expandable fusion device 1000 c include projections111 c 1 and 111 c 2 directed toward each other as well as matingrecesses 113 c 1 and 113 c 2 extending the length of the projections andthrough upper surfaces of the endplates. The recesses further contain adovetailed track 103 c 2 on one endplate and a dovetailed projection 103c 1 on the opposing endplate (best seen in FIG. 59C) so that the matingendplates only move in one dimension relative to each other, towards oraway from each other along the long axis of the dovetailed track.Whereas the projections 111 c 1 and 111 c 2 and the recesses 113 c 1 and113 c 2 have complementary shapes so that when two endplates aresuitably rotated, the projection 111 c 1 of one nests in the recess 113c 2 of the other and the recess 113 c 1 of one accepts the projection111 c 2 of the other, while allowing the lower surfaces of the twoendplates to touch and the inner and outer surfaces of the two endplatesto be aligned. It should be understood that although the stabilizationfeatures of this embodiment have been shown here to slidablyinterconnect upper and lower endplate portions, the same arrangement isalso be used to slidably interconnect the upper pairs or lower pairs ofthe endplate portions, or to slidably interconnect both the upper pairs,the lower pairs and the upper and lower endplate portions.

It should also be understood that although the various alternativegeometries of the various components are presented here as discreteembodiments, these alternative embodiments have optional features whichmay be substituted or mixed/matched with any other embodiment in thespecification. It should also be understood that substituting any of theaforementioned optional alternative features in any of the componentsmay or will necessitate the mating components to use the inverse orcomplementary geometry of those features for proper engagement and thatthe shape of that inverse or complementary geometry would followinevitably from the optional alternative feature geometry describedabove and from the detailed description of the embodiments described asutilizing that geometry. As an example, the fourth expandable fusiondevice 1000 c may utilize some or any of the actuator embodiments,height and width expansion features, configurations and embodiments aswell as the endplate stabilization features and embodiments describedhere.

Fifth Expandable Fusion Device

Turning now to FIGS. 60A-60C, which show an exemplary fifth expandablefusion device 1000 d. FIG. 60A shows an exemplary fifth expandablefusion device 1000 d in a fully expanded state and FIG. 60B shows a sideview of an exemplary fifth expandable fusion device 1000 d in a fullyexpanded state. The fifth expandable fusion device 1000 d is identicalto the previously described fourth expandable fusion device 1000 cexcept that in the fifth expandable fusion device 1000 d, the endplatescontain nested interlocking stabilization features, in which theprojections 111 c 1 and 111 c 2 described above in relation to thedevice 1000 c, also include curved protrusions 111 d 3 and 111 d 4respectively, and the recesses 113 c 1 and 113 c 2 described above inrelation to the device 1000 c, also include curved reliefs 113 d 3 and113 d 4 respectively, which are configured to accept the curvedprotrusions 111 d 3 and 111 d 4 in a nesting fashion. The curvedprotrusions are configured to tangentially contact the ramped surfacesof the ramps 300 b thereby providing additional contact points betweenthe ramps and the endplates and resulting in improved device stabilityat the upper limits of allowable height expansion. The endplates of thefifth expandable fusion device 1000 d contain no ramped surfaces andrely on the pin components to transmit expansion force between the rampsand the endplates, which may lead to undesired motion (or slop) betweenthese components due to low contact area. Adding curved features (suchas the curved protrusions 111 d 3 and 111 d 4) to the endplates allowsto approximate a continuous contact surface between the ramps and theendplates thereby improving stability as mentioned above.

It should also be understood that although the various alternativegeometries of the various components are presented here as discreteembodiments, these alternative embodiments have optional features whichmay be substituted or mixed/matched with any other embodiment in thespecification. It should also be understood that substituting any of theaforementioned optional alternative features in any of the componentsmay or will necessitate the mating components to use the inverse orcomplementary geometry of those features for proper engagement and thatthe shape of that inverse or complementary geometry would followinevitably from the optional alternative feature geometry describedabove and from the detailed description of the embodiments described asutilizing that geometry. As an example, the fifth expandable fusiondevice 1000 d may utilize some or any of the actuator embodiments,height and width expansion features, configurations and embodiments aswell as the endplate stabilization features and embodiments describedhere.

Sixth Expandable Fusion Device

Turning now to FIGS. 61A-61B, which show an exemplary sixth expandablefusion device 1000 e. FIG. 61A shows an exemplary sixth expandablefusion device 1000 e in a fully expanded state and FIG. 61B shows anexploded view of an exemplary sixth expandable fusion device 1000 e. Thesixth expandable fusion device 1000 e comprises an embodiment 100 e ofthe first endplate 100 (as well as the endplates 150, 200 and 250,whereas the endplates 100 e and 150 e are identical and the endplates250 e and 200 e are mirrors of the endplates 100 e and 150 e), which isidentical to the endplate 100 with the following exceptions. In theendplate 100 e, the slots 107 and 109 have a generally C-shapedcross-sections and have equal slopes inclined in the same direction,whereas both the slots 107 and 109 start at the upper surface 134 andslope toward the second end 104, the bottom surface 132 includes aprotrusion 145 e proximate the slot 109 and a recess 146 e proximate theslot 107, whereas the protrusion 145 e and the recess 146 e havecomplementary shapes so that when top and bottom endplates are collapsedagainst each other, the protrusion 145 a of one nests in the recess 146e of the other allowing the respective top and bottom surfaces of theopposing endplates to touch. The protrusion 145 e further includes anopening 147 e (shown in FIG. 61B on the endplate 150 a) that isgenerally aligned with the ramped slots 335 e of the ramp 300 e whenassembled and is configured to accept the pin 600, which then engage theramped slots in the ramp 300 e.

The endplate 100 e does not include tapered grooves 122, 118, 124 and120 present in previously discussed embodiments of the endplate 100, butinstead includes ramped surfaces 121 e and 123 e, which performgenerally the same function as the grooves 122, 118, 124 and 120, whichis to prevent height expansion from taking place until the device issufficiently expanded in width. This is accomplished through the rampedsurfaces 121 e and 123 e being in contact with mating ramped surfaces ofthe wedges throughout most of the width expansion process and while theyare in contact with the wedges, the ramps on the opposing sides of eachendplate are only able to move along the direction of the rampedsurfaces of the wedges and the ramped surfaces 121 e and 123 e, whileremaining static relative to one another, whereas to achieve heightexpansion the opposing ramps need to be able to move toward each otheralong the long axis of the device. Once the width expansion issubstantially completed and once the ramped surfaces 121 e and 123 e nolonger contact the wedges, the ramps are allowed to move toward eachother resulting in height expansion. The endplate 100 e further includesan opening 119 e extending from the upper surface through to the lowersurface in the direction perpendicular to the long axis. The purpose ofthe opening 119 e is to be engaged by mating protuberances 315 e of theramp 350 e or 450 e. The endplate 100 a further includes a rectilinearrelief 149 e spanning the distance between the slots 107 and 109. Thepurpose of the relief 149 e is to allow the ramps 300 e and 400 e tomate properly with the endplates.

The sixth expandable fusion device 1000 e further comprises a distalramp 350 e and a distal ramp 450 e, which are identical and willhenceforth be referred to as the distal ramp 350 e. The sixth expandablefusion device 1000 e further comprises a proximal ramp 300 e and aproximal ramp 400 e, which are identical and will henceforth be referredto as the proximal ramp 300 e. The distal ramp 350 is the same as theramp 300 b described above with the following exceptions: the distalramp 350 e does not include the protuberance 315 b or the ramped slotspresent in the ramp 300 b and instead includes a protuberance 315 e,which extends past the upper surface 309 b, past the lower surface 311 band past the outer surface 307 b and has an elongated shape extendinggenerally in the direction normal to the upper and lower surfaces. Theproximal ramp 300 e is the same as the ramp 300 b described above withthe following exceptions: in the proximal ramp 300 e, the ramped slot337 b is recessed into the outer surface 327 b as opposed to the innersurface 305 b as it is in the previously described ramp 300 b, thisresults in both the ramped slots 337 b and 338 b being on the same sideof the proximal ramp 300 e, and merging together at the mid-plane. Theproximal ramp 300 e does not include the ramped reliefs 341 b and 342 b,the branches 323 b and 321 b of the protrusion 315 b have generallyC-Shaped cross-sections, and the proximal ramp 300 e further includes aprotrusion 315 e 1 connected to the tip of the proximal ramp 300 e by anisthmus 315 e 2 and forming a first end 301 e of the proximal ramp 300e. The protrusion 315 e 1 is identical to the protrusion 315 b includinghaving the two ramped slots 338 e and 337 e which are both recessed intothe outer surface 327 e coplanar with the outer surface 327 b. The tipof the protrusion 315 e 1 forming the first end 301 e is truncated to beshorter than that of the protrusion 315 b.

The sixth expandable fusion device 1000 e further comprises the actuator500 a, the proximal wedge 550 a, the distal wedge 650 a and the pins 600configured to press into the mating openings of the endplates and toengage the ramped slots 338 b, 337 b, 338 e and 337 e of the proximalramps to provide stability and prevent device disassembly due tohyper-expansion, by bottoming out in the ramped slots at the end ofmaximum allowed travel and height expansion. As in other embodiments ofthe fusion device, after the sixth expandable fusion device 1000 e hassubstantially reached the maximum width expansion, further drawing thewedges together causes the proximal ramps and distal ramps to movetoward each other. The proximal ramps are engaged with the ramped slotsof the endplates and effect height expansion by moving relative to theendplates in both the direction of the long axis of the device and thedirection of height expansion and along the angle of the mated rampedsurfaces of the endplates and the proximal ramps, whereas the distalramps only move relative to the endplates in the direction of the heightexpansion. Optionally, in any embodiment, replacing the ramps 350 e and450 e with the ramps 350 a and 450 a, as well as adding mating rampedslot to the endplates to provide mating geometry for the ramps 350 a and450 a would result in an embodiment with desirable characteristicsincluding improved endplate stability and easier and more uniform heightexpansion.

It should also be understood that although the various alternativegeometries of the various components are presented here as discreteembodiments, these alternative embodiments have optional features whichmay be substituted or mixed/matched with any other embodiment in thespecification. It should also be understood that substituting any of theaforementioned optional alternative features in any of the componentsmay or will necessitate the mating components to use the inverse orcomplementary geometry of those features for proper engagement and thatthe shape of that inverse or complementary geometry would followinevitably from the optional alternative feature geometry describedabove and from the detailed description of the embodiments described asutilizing that geometry. As an example, the sixth expandable fusiondevice 1000 e may utilize some or any of the actuator embodiments,height and width expansion features, configurations and embodiments aswell as the endplate stabilization features and embodiments describedhere.

Seventh Expandable Fusion Device

Turning now to FIGS. 62A-62B, which show an exemplary seventh expandablefusion device 1000 f. FIG. 62A shows an exemplary seventh expandablefusion device 1000 f in a fully expanded state and FIG. 62B shows anexploded view of an exemplary seventh expandable fusion device 1000 f.In this embodiment, the ramps in the front end of the seventh expandablefusion device 1000 f engage the rear ramped surfaces of the endplatesand the ramps on the rear of the device engage the front ramped surfaceson the endplates, causing the device to expand in height as the frontand rear ramps are forced together when the actuator is actuated. Theseventh expandable fusion device 1000 f comprises an embodiment 100 f ofthe first endplate 100 (as well as the endplates 150, 200 and 250,whereas the endplates 100 f and 250 f are identical and the endplates150 f and 200 f are mirrors of the endplates 100 f and 250 f) in whichthe slots 107 and 109 have “sideways T”-shaped cross-sections, haveequal slopes and are inclined in the opposing directions, whereas theslot 107 f extends through the inner surface 132 f and the slot 109 fextends through the outer surface 134 f.

The endplate 100 f does not include tapered grooves 122, 118, 124 and120 present in previously discussed embodiments of the endplate 100, butinstead includes rounded surfaces 121 f proximate the first end 102 androunded surfaces 123 f proximate the second end 104, which performgenerally the same function as the grooves 122, 118, 124 and 120, whichis to prevent height expansion from taking place until the device issufficiently expanded in width. This is accomplished through the roundedsurfaces 121 f and 123 f being in tangent contact with mating rampedsurfaces of the wedges throughout most of the width expansion processand while they are in contact with the wedges, the ramps on the opposingsides of each endplate are only able to move along the direction of theramped surfaces of the wedges as they maintain tangent contact with therounded surfaces 121 f and 123 f, while remaining static relative to oneanother, whereas to achieve height expansion the opposing ramps need tobe able to move toward each other along the long axis of the device.Once the width expansion is substantially completed and once the roundedsurfaces 121 f and 123 f lose their tangent contact with the wedges, theramps are allowed to move toward each other resulting in heightexpansion. Optionally, in any embodiment, the rounded surfaces 121 f and123 f are also ramped planar surfaces generally parallel to the rampedsurfaces of the wedges to achieve the same height expansion-limitingeffect as described above.

The endplate 100 f further includes a rectilinear relief 149 f spanningthe distance between the slot 107 f and the second end 104 and acorresponding relief on the other side that is the same and is not seenspanning the distance between the slot 109 and the first end 102. Thepurpose of the reliefs is to allow the ramps 300 f and 350 f to mateproperly with the endplates. The endplate 100 f further includes reliefs149 f 3 in both the inner surface 132 f and the outer surface 134 f,whose axes are substantially parallel to the long axis. The reliefs 149f 3 are configured to mate with the actuator 500 a and allow theendplates to be in closer proximity to each other than would otherwisebe possible without the relief 149 f 3. The reason for there being tworeliefs 149 f 3 is that since, as discussed above, the endplate 100 f isidentical to the endplate 250 and the endplate 150 f is identical to theendplate 200 f, depending on whether the endplate 100 f is assembled inthe seventh expandable fusion device 1000 f in the left or the rightposition, the inner surface 132 f of the endplate 100 f may form eitheran inner or an outer margin of the assembled device. With this in mind,the endplate 100 f includes two reliefs 149 f 3 in order to keep theleft and right endplate components identical in this embodiment, eventhough only one of the reliefs 149 f 3 actually contacts the actuator500 a in any given endplate in any given assembly.

The seventh expandable fusion device 1000 f further comprises a proximaloutside ramp 300 f and a distal outside ramp 450 f, which are identicaland will henceforth be referred to as the outside ramp 300 f. The fusiondevice 1000 e further comprises a proximal inside ramp 400 f and adistal inside ramp 350 f, which are identical and will henceforth bereferred to as the inside ramp 350 f. Here the ramps are described asinside and outside based on whether their ramped surfaces make contactwith the inner or the outer slots in the endplates. The inside ramp 350f is the same as the ramp 300 b described above with the followingexceptions: the inside ramp 350 f does not include the ramped slots 337b and 338 b or the ramped reliefs 341 b and 342 b present in the ramp300 b, the branches 321 f and 323 f have sideways-T-shapedcross-sections configured to mate with similarly shaped slots 107 f and109 f of the endplates. The inside ramp 350 f is longer than the ramp300 b and has a truncated tip proximate the first end 301 b. The insideramp 350 f is configured to engage the inward facing slots of theendplates and to allow the outside ramp 300 f to clear the outersurfaces of the outside ramp 350 f while itself engaging the outwardfacing slots of the endplates.

The outside ramp 300 f is the same as the ramp 300 b described abovewith the following exceptions: the inside ramp 300 f does not includethe ramped slots present in the ramp 300 b, the branches 321 f and 323 fhave sideways-T-shaped cross-sections configured to mate with similarlyshaped slots 107 f and 109 f of the endplates. The inside ramp 350 f islonger than the ramp 300 b and has a truncated tip proximate the firstend. Furthermore, the protuberance 315 f of the outside ramp 300 fprotrudes past both the outer surface 307 f and the inner surface 305 fas opposed to the protuberance 315 b of the ramp 300 b which onlyprotrudes past the outer surface 307 b. The outside ramp 300 f isconfigured to engage the outward facing slots of the endplates and toallow the inside ramp 350 f to clear the inner surfaces of the outsideramp 300 f while itself engaging the inward facing slots of theendplates.

The seventh expandable fusion device 1000 f further comprises theactuator 500 a, the proximal wedge 550 a, and the distal wedge 650 a. Asin other embodiments of the fusion device, after the device 1000 e hassubstantially reached the maximum width expansion, further drawing thewedges together causes the proximal ramps and distal ramps to movetoward each other. The proximal ramps are engaged with the ramped slotsof the endplates and effect height expansion by moving relative to theendplates in both the direction of the long axis of the device and thedirection of height expansion and along the angle of the mated rampedsurfaces of the endplates and the proximal ramps. Disassembly of theseventh expandable fusion device 1000 f through hyper expansion areprevented using a variety of methods described in other embodimentsabove as well as those that will be obvious to one skilled in the art.One additional contemplated method for achieving this is to assemble thedevice in the state of height expansion that is greater than desiredmaximum allowable height, then reduce the height slightly once thedevice is fully assembled and then deform the threads of the actuator500 a in such a way so as to no longer allow the seventh expandablefusion device 1000 f to return to its initial hyper-expanded staterequired for assembly or disassembly of components.

It should also be understood that although the various alternativegeometries of the various components are presented here as discreteembodiments, these alternative embodiments have optional features whichmay be substituted or mixed/matched with any other embodiment in thespecification. It should also be understood that substituting any of theaforementioned optional alternative features in any of the componentsmay or will necessitate the mating components to use the inverse orcomplementary geometry of those features for proper engagement and thatthe shape of that inverse or complementary geometry would followinevitably from the optional alternative feature geometry describedabove and from the detailed description of the embodiments described asutilizing that geometry. As an example, the seventh expandable fusiondevice 1000 f may utilize some or any of the actuator embodiments,height and width expansion features, configurations and embodiments aswell as the endplate stabilization features and embodiments describedhere.

Eighth Expandable Fusion Device

Turning now to FIGS. 63A-63D, which show an exemplary eighth expandablefusion device 1000 g in which each of the endplates comprise a frontportion and a rear portion, the front portion and the rear portionfurther include mating cut-outs and circular openings which allow theportions to be pivotably connected with a pin (or with an integralcylindrical protrusion on one of the portions engaging a mating hole inthe other portion). The pin may be pressed or welded or machined as aprotrusion into one portion, inserted into the other portion and itsfree end swaged to prevent disassembly. The ramps include cylindricalprotrusions that engage the ramped slots in the wedges, which allow theramps to both translate and rotate relative to the wedges. The slotsalso limit how far the ramps translate relative to the wedges, includinga contemplated configuration in which no translation is allowed and theramps are only able to rotate relative to the wedges. Such configurationis achieved by adjusting the length of the slots so that at the initialcollapsed state, the ramps only pivot or rotate relative to theirrespective wedges as the width expansion occurs. The eighth expandablefusion device 1000 g functions in a fashion identical to the fusiondevice 1000 a, with the following exceptions. The ramps of the eighthexpandable fusion device 1000 g are able to both translate and rotaterelative to the wedges, this combined with the fact that each of theendplates is comprised of two pivotably connected portions results inthe eighth expandable fusion device 1000 g being able to expand in widthby both translating opposing endplates away from each other, and byallowing the endplates to articulate in to a generally diamond-shaped orsquare configuration in a width expanded state.

The eighth expandable fusion device 1000 g comprises an embodiment 100 gof the first endplate 100 (as well as the endplates 150, 200 and 250,whereas the compound endplates 100 g, 250 g, 150 g and 200 g are allidentical but rotated relative to each other for proper assembly). Thecompound endplate 100 g is identical to the endplate 100 a describedabove with the following exceptions. The compound endplate 100 gcomprises two portions 100 g 1 and 100 g 2 pivotably connected with pin600 through the center of the compound endplate 100 g. Each of theportions 100 g 1 and 100 g 2 contain complementary reliefs 149 g 1 and149 g 2 and circular openings 119 g 1 and 119 g 2, which whenconcentrically aligned allow the upper surfaces and the lower surfacesof the portions 100 g 1 and 100 g 2 to be aligned in a generallyco-planar fashion and allowed to pivot around the axis of the openings119 g 1 and 119 g 2.

The eighth expandable fusion device 1000 g further comprises anembodiment 300 g of the ramp 300 (as well as the ramps 350, 400 and 450,whereas the ramps 300 g, 350 g, 400 g and 450 g are all identical inthis embodiment but are rotated relative to each other for properassembly). The ramp 300 g is identical to the ramp 300 a described abovewith the following exceptions. The branches 316 g and 314 g form achannel 328 g having a generally rectangular cross-section as opposed tothe channel 328 a of the ramp 300 a having a T-shaped cross-section. Thesurfaces 330 a and 329 a do not include protrusions 349 a and 348 a asthey do in the ramp 300 a. The branches 316 g and 314 g further includeramped surfaces 330 g 1 and 329 g 1 in addition to the ramped surfaces330 a and 329 a of the ramp 300 a, whereas the surfaces 330 g 1 and 329g 1 are at an angle to the surfaces 330 a and 329 a. The branches 316 gand 314 g further include cylindrical protrusions 349 g and 348 grespectively. Whereas the cylindrical protrusions share the same centralaxis and are tangent to the surfaces 330 a, 329 a, 316 g and 314 g. Thepurpose of the protrusions 349 g and 348 g is to translationally andpivotably engage the mating slots of the wedges.

The eighth expandable fusion device 1000 g further comprises anembodiment 550 g of the distal wedge 550. The distal wedge 550 g (shownin detail in FIG. 64) is identical to the distal wedge 550 a with thefollowing exceptions. The distal wedge 550 g does not include rampedrecessed tracks 591 a, 592 a, 593 a and 594 a, but does includeprotrusions 564 g and 566 g which include ramped recessed tracks 591 gand 593 g respectively formed in the upper surfaces of the protrusions564 g and 566 g, and further include ramped recessed tracks 592 g and594 g respectively formed in the lower surfaces of the protrusions 564 gand 566 g. The protrusions 555 g and 554 g include ramped surfaces 596g, 597 g, which are configured to allow the endplates to move relativeto the wedges once the eighth expandable fusion device 1000 g is fullyexpanded in width. Channel 598 g of the proximal wedge does not breakthrough the protrusion 555 g.

The eighth expandable fusion device 1000 g further comprises anembodiment 650 g of the distal wedge 650. In this embodiment, theproximal wedge 650 g is identical to the proximal wedge 550 g with theexception that the distal wedge 650 a includes a central aperture thatis threaded in the direction opposite to that of the proximal wedge. Forexample, if the central aperture of the proximal wedge 550 g has aleft-handed thread, then the central aperture of the distal wedge 650 ghas a right-handed thread. Optionally, in any embodiment, having all theinsertion features present on the proximal wedge also being present onthe distal wedge along with the actuator having a second drive featureon the distal end (as discussed above) is useful in the event of arevision surgery where the revision approach is not the same as theapproach used during the original surgery. Optionally, in anyembodiment, the distal wedge may have a more bulleted distal end tofacilitate initial implantation.

The eighth expandable fusion device 1000 g further comprises theactuator 500 a and the pins 600.

It should also be understood that although the various alternativegeometries of the various components are presented here as discreteembodiments, these alternative embodiments have optional features whichmay be substituted or mixed/matched with any other embodiment in thespecification. It should also be understood that substituting any of theaforementioned optional alternative features in any of the componentsmay or will necessitate the mating components to use the inverse orcomplementary geometry of those features for proper engagement and thatthe shape of that inverse or complementary geometry would followinevitably from the optional alternative feature geometry describedabove and from the detailed description of the embodiments described asutilizing that geometry. As an example, the eighth expandable fusiondevice 1000 g may utilize some or any of the actuator embodiments,height and width expansion features, configurations and embodiments aswell as the endplate stabilization features and embodiments describedhere.

Ninth Expandable Fusion Device

Turning now to FIGS. 65A-65E, which show an exemplary ninth expandablefusion device 1000 h. FIG. 65A shows an initial collapsed state of anexemplary ninth expandable fusion device 1000 h, FIG. 65B shows a fullyexpanded state of an exemplary ninth expandable fusion device 1000 h,FIG. 65C shows a partially assembled view of an exemplary ninthexpandable fusion device 1000 h in a collapsed state, FIG. 65D shows apartially assembled view of an exemplary ninth expandable fusion device1000 h is a state of full linear width expansion and FIG. 65E shows apartially assembled view of an exemplary ninth expandable fusion device1000 h in a state of full linear and angular expansion. In the ninthexpandable fusion device 1000 h each of the endplates comprise a frontportion and a rear portion, the front portion and the rear portionfurther include mating cut-outs and circular openings which allow theportions to be pivotably connected with a pin (or with an integralcylindrical protrusion on one of the portions engaging a mating hole inthe other portion). The pin may be pressed or welded or machined as aprotrusion into one portion, inserted into the other portion and itsfree end swaged to prevent disassembly. The ramps include cylindricalprotrusions that engage the ramped slots in the wedges, which allow theramps to both translate and rotate relative to the wedges. The slotsalso limit how far the ramps translate relative to the wedges. The ninthexpandable fusion device 1000 h functions in a fashion identical to thethird expandable fusion device 1000 b, with the following exceptions.The ramps of the ninth expandable fusion device 1000 h are able to bothtranslate and rotate relative to the wedges, this combined with the factthat each of the endplates is comprised of two pivotably connectedportions results in the ninth expandable fusion device 1000 h being ableto expand in width by both translating opposing endplates away from eachother, and by allowing the endplates to articulate in to a generallydiamond-shaped or square configuration in a width expanded state.

The ninth expandable fusion device 1000 h comprises an embodiment 100 hof the first endplate 100 (as well as the endplates 150, 200 and 250,whereas the compound endplates 100 h, 250 h, 150 h and 200 h are allidentical but rotated relative to each other for proper assembly). Thecompound endplate 100 h is identical to the endplate 100 b describedabove including having the rounded surfaces 121 b and 123 b with theexception that it comprises two portions that are pivotably connectedexactly as described above for the endplate 100 g.

The ninth expandable fusion device 1000 h further comprises anembodiment 300 h of the ramp 300 (as well as the ramps 350, 400 and 450,whereas the ramps 300 h, 350 h, 400 h and 450 h are all identical inthis embodiment but are rotated relative to each other for properassembly). The ramp 300 h is identical to the ramp 300 b described abovewith some exceptions. The ramp 300 h differs from the ramp 300 b inexactly the same ways that the ramp 300 g described above differs fromthe ramp 300 a described above including having the cylindricalprotrusions 349 g (best seen in FIG. 65C) and 348 g (shown in figurespertaining to the discussion of the device 1000 g). It should beunderstood that if in the initial collapsed state of the ninthexpandable fusion device 1000 h, the rounded surfaces 121 b and 123 b ofthe endplates 100 h are concentric or near concentric with thecylindrical protrusions 349 g and 348 g of the ramp 300 h (thisarticulation is best seen in FIGS. 65C, 65D and 65E), the ninthexpandable fusion device 1000 h will be able to expand in width bothlinearly and angularly starting immediately at the initial collapsedstate due to the fact that in this scenario, both the ramp and theendplate portions will be able to rotate relative to the wedges around acommon axis. Whereas if the rounded surfaces 121 b and 123 b of theendplates 100 h are not concentric or with the cylindrical protrusions349 g and 348 g of the ramp 300 h, the ninth expandable fusion device1000 h will start width expansion in a linear fashion and only be ableto expand angularly after the contact is lost between the roundedsurfaces of the endplates and the wedges. This is because for therounded surfaces of the endplates and the cylindrical protrusions of theramps are not coaxial, but still maintain simultaneous tangent contactwith the ramped surfaces of the wedges and are therefore unable torotate relative to the wedges until the ninth expandable fusion device1000 h is sufficiently expanded in width where the rounded surfaces losecontact with the ramped surfaces of the wedges.

The ninth expandable fusion device 1000 h further comprises the proximalwedge 550 g, the distal wedge 650 g, the actuator 500 a, and the pins600.

It should also be understood that although the various alternativegeometries of the various components are presented here as discreteembodiments, these alternative embodiments have optional features whichmay be substituted or mixed/matched with any other embodiment in thespecification. It should also be understood that substituting any of theaforementioned optional alternative features in any of the componentsmay or will necessitate the mating components to use the inverse orcomplementary geometry of those features for proper engagement and thatthe shape of that inverse or complementary geometry would followinevitably from the optional alternative feature geometry describedabove and from the detailed description of the embodiments described asutilizing that geometry. As an example, the ninth expandable fusiondevice 1000 h may utilize some or any of the actuator embodiments,height and width expansion features, configurations and embodiments aswell as the endplate stabilization features and embodiments describedhere.

Tenth Expandable Fusion Device

Turning now to FIG. 66A, which shows an exemplary tenth expandablefusion device 1000 k in a fully expanded state, whereas the tenthexpandable fusion device 1000 k comprises an upper endplate 100 kcomprising two portions 100 k 1 and 100 k 2 connected together into asingle component by a series of angled deformable struts 100 k 3 andfurther comprising a lower endplate 200 k comprising two portions 200 k1 and 200 k 2 connected together into a single component by a series ofangled deformable struts 200 k 3. The portions 100 k 1, 100 k 2 and 200k 1 and 200 k 2 may be identical to any of the embodiments of theendplates 100, 150, 200, and 250 described above. The angled deformablestruts 100 k 3 and 200 k 3 are chevron or V-shaped in this embodimentbut are of any other suitable shape including U-Shaped, W-shaped, andZ-Shaped etc. The struts are configured to deform upon width expansionof the device with the angles between the surfaces of the strutsincreasing through the width expansion process from some initial angleat the initial collapsed state (shown in FIG. 66B) to a larger angle ata full width expanded state (shown in FIG. 66C). With the exception ofthe two portions of the upper and lower endplates being integrallyconnected by angled deformable struts, the components comprising thetenth expandable fusion device 1000 k are identical to any of theirembodiments described above. During the width expansion step, the seriesof angled deformable struts connecting the portions comprising the upperand lower endplates are plastically deformed by the action of theactuator and the wedges to permanently bring the upper and the lowerendplates from the initial collapsed state (shown in FIG. 66D) into awidth expanded state.

It should also be understood that although the various alternativegeometries of the various components are presented here as discreteembodiments, these alternative embodiments have optional features whichmay be substituted or mixed/matched with any other embodiment in thespecification. It should also be understood that substituting any of theaforementioned optional alternative features in any of the componentsmay or will necessitate the mating components to use the inverse orcomplementary geometry of those features for proper engagement and thatthe shape of that inverse or complementary geometry would followinevitably from the optional alternative feature geometry describedabove and from the detailed description of the embodiments described asutilizing that geometry. As an example, the tenth expandable fusiondevice 1000 k may utilize some or any of the actuator embodiments,height and width expansion features, configurations and embodiments aswell as the endplate stabilization features and embodiments describedhere.

Eleventh Expandable Fusion Device

Turning now to FIG. 67A, which shows an exemplary eleventh expandablefusion device 1000 m in a fully expanded state, whereas the eleventhexpandable fusion device 1000 m comprises an endplate complex 100 m(shown in FIG. 67B) comprising upper portions 100 m 1 and 100 m 2 andlower portions 200 m 1 and 200 m 2. Whereas all four portions areintegrally connected together by series of angled (or, in otherembodiments, curved) deformable struts, whereas the two upper portionsare connected together by angled deformable struts 250 m 1 and the twolower portions are connected together by angled deformable struts 250 m1 and whereas the upper portions are connected to the lower portions byangled deformable struts 250 m 2. The portions 100 m 1, 100 m 2 and 200m 1 and 200 m 2 may be identical to any of the embodiments of theendplates 100, 150, 200 and 250 described above. The angled deformablestruts 250 m 1 and 250 m 2 are chevron or V-shaped in this embodimentbut are of any other suitable shape including U-Shaped, W-shaped, andZ-Shaped etc. The struts 250 m 1 are configured to deform with widthexpansion and the struts 250 m 2 are configured to deform with heightexpansion of the device with the angles between the surfaces of thestruts increasing through the expansion process from some initial angleat the initial collapsed state (shown in FIG. 67C) to a larger angle ata full width expanded state (shown in FIG. 67D) and at a full width andheight expanded state. With the exception of the portions of theendplates being integrally connected by angled deformable struts intothe endplate complex 100 m, the components comprising the eleventhexpandable fusion device 1000 m are identical to any of theirembodiments described above. During the device expansion, the series ofangled deformable struts connecting the portions comprising the endplatecomplex are plastically deformed by the action of the actuator, thewedges and the ramps to permanently bring the endplate complex 100 mfrom the initial collapsed state into a width expanded state and theninto a width and height expanded state.

It should also be understood that although the various alternativegeometries of the various components are presented here as discreteembodiments, these alternative embodiments have optional features whichmay be substituted or mixed/matched with any other embodiment in thespecification. It should also be understood that substituting any of theaforementioned optional alternative features in any of the componentsmay or will necessitate the mating components to use the inverse orcomplementary geometry of those features for proper engagement and thatthe shape of that inverse or complementary geometry would followinevitably from the optional alternative feature geometry describedabove and from the detailed description of the embodiments described asutilizing that geometry. As an example, the eleventh expandable fusiondevice 1000 m may utilize some or any of the actuator embodiments,height and width expansion features, configurations and embodiments aswell as the endplate stabilization features and embodiments describedhere.

Twelfth Expandable Fusion Device

Turning now to FIGS. 68-72C, which show an exemplary twelfth expandablefusion device 1000 n and its components. FIG. 68 shows an initialcollapsed state of an exemplary twelfth expandable fusion device 1000 n,which is identical to an third expandable fusion device 1000 b describedabove with the exceptions described below. The twelfth expandable fusiondevice 1000 n comprises a proximal wedge 550 n, which is identical tothe proximal wedge 550 a with the following exceptions. The proximalwedge 550 n (shown in FIGS. 69A and 69B) includes side apertures 570 nand 572 n that are generally circular in cross-section, do not breakthrough the side walls of the wedge (although in other embodiments theymay break out), and angle toward the midline of the proximal wedge 550n. The proximal wedge 550 n further includes a stepped central aperture568 n, which further includes a through hole 568 n 1 and a blind bore568 n 2 proximate the first end 562 n, whereas the blind bore 568 n 2includes a threaded section proximate the first end 562. The proximalwedge 550 n does not include channels 598 a and 599 a, which are presentin the proximal wedge 550 a.

The twelfth expandable fusion device 1000 n further comprises a distalwedge 650 n (shown in FIGS. 70A and 70B), which is identical to theproximal wedge 550 n with the following exceptions. The distal wedge 650n does not include a central aperture and instead includes a threadedblind bore 668 n through the second end 660 n, which is generallyaligned with the central aperture 568 n of the proximal wedge 550 n. Thedistal wedge 650 n further includes a relief groove 662 n 1 proximatethe first end 662 n intended to compensate for the thickness of atension member looped around the wedge and engaging the side apertures.

The twelfth expandable fusion device 1000 n further includes a flexibletension member 715 n, looped through the side apertures 670 n and 672 nof the distal wedge 650, whereas the free ends of the tension member 715n further pass through the side apertures 570 n and 572 n and extendingout of the first end 562 n of the proximal wedge 550 n, whereas thesefree ends may then be tied or clamped or otherwise detained or coupledto an actuator of an inserter/tensioner tool (not shown). The flexibletension member 715 n may comprise a suture, tape, fiber rope,monofilament or a bundle of either of the above and may be made out ofone or more of the following: polymers (e. g. UHMWPE, PET, Nylon, PEEK,Kevlar, etc.), metals (e. g. Titanium, Titanium alloys, Stainless steel,CoCrMo, etc.) or any other fiber such as for example, silk, carbonfiber, etc.

The twelfth expandable fusion device 1000 n further comprises a setscrew 700 n (best seen in FIG. 71), which is identical to the set screw700 described above with the following exceptions, the drive feature 708n (which may be a hexagon, hexalobe, trilobe, square, double-square,etc.) goes all the way through the set screw and the set screw 700 n isrelatively larger than the set screw 700 so as to suitably function asdescribed below. The set screw 700 n is threaded into the threadedportion of the bore 568 n 2 of the proximal wedge 550 n and isconfigured to (when actuated or tightened) make contact with theflexible tension member 715 n as it passes through the side openings 570n and 572 n of the proximal wedge 550 n at the pinch points indicated inFIG. 72C. The thru drive feature of the set screw 700 n is configured topass a threaded shaft 840 n (first seen in FIG. 71, which shows thetwelfth expandable fusion device 1000 n in a fully collapsed stateengaged with the threaded shaft 840 n of a tensioner instrument) of atensioner instrument (not shown in its entirety) and allow it to accessthe threaded hole 668 n of the distal wedge (best seen in FIG. 72A,which shows a section view of the twelfth expandable fusion device 1000n in a fully collapsed state engaged with the threaded shaft 840 n ofthe tensioner instrument) and further allows graft material to bedelivered through it and into the interior of the device 1000 n afterthe device is expanded (seen in a section view of the twelfth expandablefusion device 1000 n in FIG. 72B), the threaded shaft 840 n withdrawnand the set screw 700 n is actuated or tightened to lock the flexibletension member 715 n by contacting it at the pinch points indicated in asection view of the twelfth expandable fusion device 1000 n in FIG. 72Cand thereby causing the flexible tension member 715 n to hold thetension generated by the vertebral bodies applying compressive force tothe endplates and thereby allowing the twelfth expandable fusion device1000 n to remain in its expanded state.

Unlike the fusion third expandable fusion device 1000 b, the twelfthexpandable fusion device 1000 n does not comprise the actuator 500 a,instead, the functionality of the threaded (or more generally—linear)actuator 500 a of effecting the expansion of the fusion device 1000 nand keeping the twelfth expandable fusion device 1000 n at the desiredstate of expansion is split between the threaded shaft 840 n of thetensioner instrument (not shown here in its entirety), which threadsinto the distal wedge 650 n and has linear tension applied to it by thetensioner instrument while the body of said tensioner instrumentsimultaneously bears on the proximal wedge 550 n to cause the proximaland distal wedges 550 n and 650 n to move toward each other causing thetwelfth expandable fusion device 1000 n to expand in a manner describedabove for other embodiments of the device, and the flexible tensionmember 715 n which, being attached to the tensioner instrument duringthe device expansion allows to keep the twelfth expandable fusion device1000 n in the desired state of expansion by means of tightening the setscrew 700 n. It should be understood that the tension member 715 n mayalso be locked by means other than the set screw 700 n, including tyingthe ends of the tension member into a knot or employing other means ofpreventing loss of tension or slippage of the tension member such asthose widely understood, known and utilized in the designs of sutureanchors and buttons used in orthopedic surgery. The ends of the tensionmember 715 n may need to be trimmed off following the expansion andlocking step.

It should also be understood that although the various alternativegeometries of the various components are presented here as discreteembodiments, these alternative embodiments have optional features whichmay be substituted or mixed/matched with any other embodiment in thespecification. It should also be understood that substituting any of theaforementioned optional alternative features in any of the componentsmay or will necessitate the mating components to use the inverse orcomplementary geometry of those features for proper engagement and thatthe shape of that inverse or complementary geometry would followinevitably from the optional alternative feature geometry describedabove and from the detailed description of the embodiments described asutilizing that geometry. As an example, the twelfth expandable fusiondevice 1000 n may utilize some or any of the actuator embodiments,height and width expansion features, configurations and embodiments aswell as the endplate stabilization features and embodiments describedhere.

Thirteenth Expandable Fusion Device

With reference to FIGS. 73A-74B, FIGS. 73A, 73B, 73C and 73D showrespectively an initial collapsed state, a fully width expanded state, afully height expanded state and an exploded view of an exemplarythirteenth expandable fusion device fusion device 1000 p comprising theendplates 100 a, 150 a, 200 a and 250 a (which are all identical in thisembodiment), ramps 300 p, 350 p, 400 p and 450 p (which are allidentical in this embodiment), proximal wedge 550 p, distal wedge 650 p(distal and proximal wedges are identical in this embodiment) and theactuator 500 a. The thirteenth expandable fusion device fusion device1000 p is identical to the second expandable fusion device fusion device1000 a described above with the following exceptions. The ramp 300 p isidentical to the ramp 300 a described above with the exception thatsurfaces 320 p, 329 p and 330 p are not ramped but are generallytransverse (they are either perpendicular as shown or angled to the longaxis depending on whether the mating surfaces of the particularembodiment of the wedges are perpendicular or angled with respect to thelong axis of the device) to the long axis of the thirteenth expandablefusion device fusion device 1000 p. The distal wedge 650 p is identicalto the distal wedge 650 a described above with the following exceptions.It should be noted that above, the distal wedge 650 a was describedsimply as identical to the proximal wedge 550 a, whereas the proximalwedge 550 a was described in detail. The surfaces 680 p and 682 p arenot ramped with respect to each other as the corresponding surfaces ofthe wedge 650 a are, but are instead generally parallel and generallytransverse (Optionally, in any embodiment, they are either perpendicularas shown or angled with respect to the long axis of the device) to thelong axis of the thirteenth expandable fusion device fusion device 1000p. The surfaces 680 p and 682 further include slots 691 p and 692 prespectively, which break through one side of the wedge, but not theother side of the wedge and serve the purpose of limiting thetranslation of the ramps relative to the wedge on the side where theslots don't break through the side wall of the wedge 650 p. To limit thetranslation of the ramps relative to the wedge on the other side of thewedge, the opening of the slots may be plastically deformed or “swaged”after the device is assembled to prevent disassembly. Furthermore, theupper and lower surfaces 652 p and 690 p of the distal wedge 650 p donot include projections or channels as they do in wedge 650 a. Distalwedge 650 p is identical to the proximal wedge 550 p.

Since the mating sliding surfaces of the ramps and their respectivemating wedges are generally collectively parallel and transverse(perpendicular as shown or could be angled) to the long axis of thethirteenth expandable fusion device fusion device 1000 p, thisarrangement causes the thirteenth expandable fusion device fusion device1000 p to not be able to expand in width when the actuator 500 a isactuated. Instead, when the actuator 500 a is actuated, the device 1000p only expands in height, which is different from the way all of thepreviously described embodiments behave. Since the mating slidingsurfaces of the ramps and the wedges are collectively parallel and aretransverse to the long axis, the thirteenth expandable fusion devicefusion device 1000 p are expanded in width by means of application ofexternal force, for example, by means of an inserter/expanderinstrument. As such, the articulations between the ramps and the wedgesno longer act as an expansion mechanism, but simply keep the device'scomponents in proper alignment while preventing disassembly at the upperlimit of width expansion affected by the instrument. The width expansionis now independent from the height expansion, which is beneficial insome applications. FIGS. 74A and 74B show the thirteenth expandablefusion device fusion device 1000 p assembled with inserter-expanderinstrument 840 p in respectively the initial collapsed state and in thefully width expanded state. The inserter-expander instrument 840 p (notshown in its entirety) comprises a pair of front wedges 840 p 1 and apair of rear wedges 840 p 2, which are drawn together or forced apartusing a screw-operated, grip-operated or any other mechanism (notshown). The inserter-expander instrument is engaged with the thirteenthexpandable fusion device fusion device 1000 p in a fully width expandedstate of the device; the device is then collapsed back to its initialstate for insertion. Once inserted into the disc-space, the front wedgesand the rear wedges of the instrument are drawn together causing thethirteenth expandable fusion device fusion device 1000 p to expand inwidth up an expansion width at which, the front wedges no longer makecontact with the device 1000 p (state best seen in FIG. 74B) and arewithdrawn. Once that happens, the device is expanded in height. Thisarrangement means that in order for the instrument 840 p to bedisengaged from the thirteenth expandable fusion device fusion device1000 p, the device has to be sufficiently expanded in width to allow thefront wedge to be withdrawn. Optionally, in any embodiment, multipledifferent front wedge widths may be supplied to the end-user to allowthem to make a determination of what target expansion width is bestsuited for a particular application. It should be noted that having thewidth expansion operated by two opposing wedges does not allow todecrease the width from wider to narrower state without a dove-tail,hook or otherwise articulation between the front and rear wedges and thedevice, which would allow the instrument to exert both tension andcompression onto the device and thereby allow the instrument to bothexpand and collapse the width of the device. This functionality will beexplored in embodiments below. It should also be mentioned at this pointthat all expansion mechanisms and configurations described above withthe exception of the device 1000 p are configured (albeit with variousdegrees of practicality) to allow the device expansion in both width andheight to be reversed by reversing the actuation direction, this is sobecause all of the ramped articulations described above except in thethirteenth expandable fusion device fusion device 1000 p have both thefront-facing and rear-facing ramped contact surfaces allowing thesearticulations to take both tensile and compressive forces resulting inthe ability to both expand and collapse those devices by actuating theactuators in a “forward” and “reverse” directions respectively.

It should also be understood that although the various alternativegeometries of the various components are presented here as discreteembodiments, these alternative embodiments have optional features whichmay be substituted or mixed/matched with any other embodiment in thespecification. It should also be understood that substituting any of theaforementioned optional alternative features in any of the componentsmay or will necessitate the mating components to use the inverse orcomplementary geometry of those features for proper engagement and thatthe shape of that inverse or complementary geometry would followinevitably from the optional alternative feature geometry describedabove and from the detailed description of the embodiments described asutilizing that geometry. As an example, the thirteenth expandable fusiondevice fusion device 1000 p may utilize some or any of the actuatorembodiments, height and width expansion features, configurations andembodiments as well as the endplate stabilization features andembodiments described here.

Fourteenth Expandable Fusion Device

With reference to FIGS. 75A-75E, FIGS. 75A, 75B, 75C, 75D and 75E showrespectively an initial collapsed state, a fully width expanded state, afully height expanded state, the fully width and height expanded stateand an exploded view of an exemplary fourteenth expandable fusion device1000 r comprising the endplates 100 r, 150 r, 200 r and 250 r (which areall identical in this embodiment), ramps 300 r, 350 r, 400 r and 450 r(which are all identical in this embodiment), proximal wedge 550 p,distal wedge 650 p (distal and proximal wedges are identical in thisembodiment) and the actuator 500 a. The fourteenth expandable fusiondevice 1000 r is identical to the thirteenth expandable fusion device1000 p described above with the following exceptions. The endplate 100 rhas a first end 102 r and a second end 104 r. The first endplate 100 rfurther comprises an upper surface 134 r, a lower surface 132 r and aninner surface 130 r connecting the first end and the second end. As inall other embodiment described here, the upper surface includes surfacefeatures increasing the roughness of the surface. The inner surfaceincludes a cylindrical relief 149 r whose axis is parallel to the longaxis. The first endplate 100 further comprises a first ramped surface110 r proximate the first end and a second ramped surface 112 rproximate the second end. The ramped surfaces 110 r and 112 r furtherinclude dovetailed ramped slots 107 r and 109 r respectively. Asdiscussed above, although in this embodiment, the slots are dovetailedand have generally trapezoidal cross-sections, they may also haveT-shaped, Y-shaped, or any other suitable cross-section that would allowthe mating articulations to possess both the leading and trailingcontact surfaces. The endplate 100 r further includes an opening 119 rextending through the side surfaces in the direction transverse to thelong axis. Relief 149 r. The edges formed by intersection of the rampedsurfaces 110 r and 112 r and the inner surface 130 r include chamfers121 r and 123 r configured to mate with the inserter-expander instrument840 p described above.

The ramp 300 r is identical to the ramp 300 p described above with thefollowing exceptions. The branches 321 r and 323 r do not have U-shapedcross-sections as the corresponding features of the ramp 300 p do,instead the branches 321 r and 323 r include ramped surfaces 302 r and304 r respectively, whereas these ramped surfaces include dovetailedfins 302 r 1 and 304 r 1 respectively. The dovetailed fins areconfigured to mate with the dovetailed ramped slots of the endplates.The ramp 300 r does not include a recessed slot present in the ramp 300p. The fourteenth expandable fusion device 1000 r has similarfunctionality to the thirteenth expandable fusion device 1000 pdescribed above including the reliance on external expander instrumentfor width expansion.

It should also be understood that although the various alternativegeometries of the various components are presented here as discreteembodiments, these alternative embodiments have optional features whichmay be substituted or mixed/matched with any other embodiment in thespecification. It should also be understood that substituting any of theaforementioned optional alternative features in any of the componentsmay or will necessitate the mating components to use the inverse orcomplementary geometry of those features for proper engagement and thatthe shape of that inverse or complementary geometry would followinevitably from the optional alternative feature geometry describedabove and from the detailed description of the embodiments described asutilizing that geometry. As an example, the fourteenth expandable fusiondevice 1000 r may utilize some or any of the actuator embodiments,height and width expansion features, configurations and embodiments aswell as the endplate stabilization features and embodiments describedhere.

Fifteenth Expandable Fusion Device

With reference to FIGS. 76A-76D, FIGS. 76A, 76B, 76C and 76D showrespectively an initial collapsed state, a fully width expanded stateand a fully height expanded state and an exploded view of an exemplaryfifteenth expandable fusion device 1000 s comprising endplates 100 r,150 r, 200 r and 250 r (which are all identical in this embodiment),ramps 300 s, 350 s, 400 s and 450 s (which are all identical in thisembodiment), proximal wedge 550 s, distal wedge 650 s (distal andproximal wedges are identical in this embodiment) and the actuator 500a. The fifteenth expandable fusion device 1000 s is identical to thefourteenth expandable fusion device 1000 r described above with thefollowing exceptions. The proximal wedge 550 s is identical to theproximal wedge 550 a described above with the following exceptions, theupper and lower surfaces of the wedge 550 s include no projections orchannels as they do in the wedge 550 a and the opposing ramped surfacesof the wedge 550 s have larger included angle “A” between them than theydo in the wedge 550. This angle is best seen in FIG. 76A and iscontemplated as being greater than 100 degrees and less than 179 degreesand more preferably greater than 140 degrees and most preferably greaterthan 160 degrees (150 degree angle is shown for illustrative purposes).The ramp 300 s is identical to the ramp 300 r with the followingexceptions: the surfaces 330 s, 320 s and 329 s are not perpendicular tothe long axis as they are in the ramp 300 r, but are instead ramped atan angle equal to half of the angle “A” discussed above relative to thelong axis, this is best seen in FIG. 76A. The ramp 300 s furtherincludes ramped undercuts 337 s 1 and 337 s 2, which are configured tomate with an expander instrument and may have either a rectangularsection or L-shaped, T-shaped or dovetailed section. The endplate 100 sis identical to the endplate 100 r described above with the exceptionthat the endplate 100 s also includes ramped undercuts 147 s 1 and 147 s2, which are configured to mate with an expander instrument and may haveeither a rectangular section or L-shaped, T-shaped or dovetailedsection. Undercuts 337 s 1, 337 s 2, 147 s 1 and 147 s 2 when havingrectangular sections, serve the purpose of preventing the device fromexpanding in height while the width expansion is affected by theexpander instrument. When these undercuts have L-shaped, dovetailed orsimilar sections, they serve an additional purpose of allowing theexpander instrument to both increase and decrease the width of thedevice by reversing the direction of actuation. As discussed above, thisis because, the L-shaped, T-shaped, dovetailed, etc. sections containboth the front and rear contact surfaces allowing to capture the matingcomponents and allow tension or compression to be applied to theinterface.

The significance and usefulness of the large included angle “A” betweenthe ramped surfaces of the wedges is not obvious and requires anadditional clarification. Functionality and clinical utility of many ofthe embodiments of the expandable fusion device described here (e. g.1000 a, 1000 b, 1000 c, 1000 d, 1000 e, etc.) rely on the fact thatcomplete or significant width expansion has to occur before the heightexpansion is initiated. This is achieved through the endplatesmaintaining sliding contact with mating surfaces of the wedges duringwidth expansion step and when configured in the ways described above,this contact while maintained prevents the ramps from moving closer toeach other (which would be necessary to affect height expansion). In thecourse of width expansion, this contact between the endplates and thewedges is eventually lost and the height expansion is allowed to start.However, the fifteenth expandable fusion device 1000 s does not includesuch delay mechanism, and both the width and height expansion appear tobe able to occur simultaneously by turning the actuator. If we imaginean alternative fifteenth expandable fusion device 1000 s 1 (not shown),which is identical to the fifteenth expandable fusion device 1000 sexcept that its angle “A” is relatively small (e. g. around 90 degrees)and imagine this alternate fifteenth expandable fusion device 1000 s 1in a state of expansion where the width of the device is less than atthe state of full width expansion and where the device is at leastsomewhat expanded in height. If we now keep the actuator static, whichit generally would be while not actuated (i. e. due to thread friction),and apply compression to the device endplates, such as the adjacentvertebral endplates would apply in clinical use, the alternate fifteenthexpandable fusion device 1000 s 1 will tend to collapse in height andsimultaneously expand in width until either the full width expansion orthe full collapse of height is reached (whichever happens first based onthe initial extent of height and width expansion). This happens becausein any device state where full width expansion is not yet reached, foreach position of the actuator relative to the wedges andconsequently—for every separation distance between the proximal and thedistal wedges, there exists a range of expansion states that areachievable. In other words, in this situation, the alternate fifteenthexpandable fusion device 1000 s 1 is not at equilibrium and its heightexpansion are “converted” into width expansion by the followingmechanism of action. In such a state, when compression is applied to theendplates in the height direction, the ramp components see a forceurging them apart generated by inclined surfaces involved in heightexpansion, since the actuator remains static, the ramps only move apartby sliding relative to the wedges into a state of greater widthexpansion thereby increasing the distance between the ramps anddecreasing the height of the device. In a similar height-only or awidth-only expansion mechanism, this reversal of expansion is preventeddue to the friction in the threads of the actuator, which has to do withthe “locking” property of threads used. Locking threads arecharacterized by a low “helical angle”, which for example prevents anaverage screw from being axially pushed into a mating thread withoutapplying any torque (it should be noted that no amount of pure axialforce will cause a locking thread to follow a helical path into a matingthread). This is in contrast to a non-locking (or overhauling) threadsuch as one used in a cork-screw, which are forced to twist into awork-piece through application of pure axial force. But in this case,since the actuator does not move, and the dis-equilibrium is intrinsicto the mechanism, the locking property of the actuator threads cannotprevent the loss of height. Similar to the threads having theirmechanical efficiency controlled by angle of the thread helix (with lowhelical angles imparting a locking property to the threads), the rampsor “inclined planes” (of which a wedge mechanism is an adaptation) arealso known to possess mechanical efficiency (or advantage), which isexpressed as the length of the incline divided by its rise or moresimply—by the included angle of the wedge. The larger the includedangle, the less mechanical advantage the wedge mechanism has.Furthermore, for any wedge mechanism and materials used (and frictiongenerated), there exists some maximum included angle at which the wedgewill cease acting as a wedge in that attempting to push such a wedgebetween two objects will not cause these objects to be forced apart nomatter how high the applied load is due to frictional forces, loads andmaterial strength.

Bringing this back to the fifteenth expandable fusion device 1000 s,because the proximal and distal wedges 550 s and 650 s utilize a highangle “A”, they do not function as a width expansion mechanism andinstead function as a locking mechanism preventing the fifteenthexpandable fusion device 1000 s from spontaneously losing height andgaining width. This means that if in the initial collapsed state, theactuator 500 is turned, the fifteenth expandable fusion device 1000 swill only expand in height and not in width and no reasonablecompressive force acting in the height direction will cause the deviceto lose height and gain width as discussed above. The fifteenthexpandable fusion device 1000 s relies on an external inserter-expanderinstrument 840 s (seen in FIGS. 77A and 77B) to affect the widthexpansion.

The inserter-expander instrument 840 s (not shown in its entirety)comprises a pair of front wedges 840 s 1 and a pair of rear wedges 840 s2, which are drawn together or forced apart using a screw-operated,grip-operated or any other mechanism (not shown). The instrument 840 sis configured to simultaneously actuate (here: turn) the actuator in theforward or reverse direction and translate the front and the rear wedgestogether or apart. Turning the actuator in the process of widthexpansion does not cause or substantially contribute to width expansionitself (due to high angles “A” of the wedges and the resulting near-zeromechanical efficiency of these wedges), but simply allows the proximaland the distal wedges to move toward each other providing room for thewidth expansion to be effected by the forces supplied by the instrument840 s. The inserter-expander instrument is engaged with the fifteenthexpandable fusion device 1000 s in a fully width expanded state of thedevice, the device is then collapsed back to its initial state forinsertion into the disc space (best seen in FIG. 77A). Once insertedinto the disc-space, the front wedges and the rear wedges of theinstrument are drawn together causing the fifteenth expandable fusiondevice 1000 s to expand in width up to an expansion width at which, thefront wedges no longer make contact with the device 1000 p (state bestseen in FIG. 77B) and are withdrawn. Once that happens, the device isexpanded in height. This arrangement means that in order for theinstrument 840 s to be disengaged from the device 1000 p, the device hasto be sufficiently expanded in width to allow the front wedge to bewithdrawn. Optionally, in any embodiment, multiple different front wedgewidths may be supplied to the end-user to allow them to make adetermination of what target expansion width is best suited for aparticular application. It should be noted that having the widthexpansion operated by two opposing wedges does not allow to decrease thewidth from wider to narrower state unless a dove-tail, hook, L-shaped orotherwise articulation between the front and rear wedges and the deviceis used, which would allow the instrument to exert both tension andcompression onto the device and thereby allow the instrument to bothexpand and collapse the width of the device as discussed above).

It should also be understood that although the various alternativegeometries of the various components are presented here as discreteembodiments, these alternative embodiments have optional features whichmay be substituted or mixed/matched with any other embodiment in thespecification. It should also be understood that substituting any of theaforementioned optional alternative features in any of the componentsmay or will necessitate the mating components to use the inverse orcomplementary geometry of those features for proper engagement and thatthe shape of that inverse or complementary geometry would followinevitably from the optional alternative feature geometry describedabove and from the detailed description of the embodiments described asutilizing that geometry. As an example, the fifteenth expandable fusiondevice 1000 s may utilize some or any of the actuator embodiments,height and width expansion features, configurations and embodiments aswell as the endplate stabilization features and embodiments (such asshown for example in embodiments 1000 c and 1000 d) described here.

Sixteenth Expandable Fusion Device

With reference to FIGS. 78, 79A and 79B, FIG. 78 shows the initialcollapsed state of an expandable device 1000 t, FIG. 79A shows theinitial collapsed state of an exemplary sixteenth expandable fusiondevice 1000 t with expander instrument attached and FIG. 79B shows awidth-expanded state of the device 1000 t with expander instrumentattached. The sixteenth expandable fusion device 1000 t comprisesendplates 100 t, 150 t (best seen in FIG. 79B), 200 t and 250 t (whichare all identical in this embodiment), ramps 300 s, 350 s, 400 s and 450s (which are all identical in this embodiment), proximal wedge 550 s,distal wedge 650 s (distal and proximal wedges are identical in thisembodiment) and the actuator 500 a. The sixteenth expandable fusiondevice 1000 t is identical to the device 1000 s described above with thefollowing exceptions. The endplate 100 t includes a ramped slot 107 t 2formed in the upper surface 134 t. This ramped slot is configured toengage the inserter-expander instrument 840 t (best seen in FIGS. 79Aand 79B).

The inserter-expander instrument 840 t (not shown in its entirety)comprises a pair of front bifurcated ramps 840 t 1 which are pushed orpulled while the main body of the instrument (not shown) is attached toand bears against the proximal wedge. The instrument 840 t is configuredto simultaneously actuate (here: turn) the actuator in the forward orreverse direction and translate the bifurcated ramps forward or backwarddepending on actuation direction. Turning the actuator in the process ofwidth expansion does not cause or substantially contribute to widthexpansion itself (due to high angles “A” of the wedges and the resultingnear-zero mechanical efficiency of these wedges), but simply allows theproximal and the distal wedges to move toward each other providing roomfor the width expansion to be effected by the forces supplied by theinstrument 840 t. The inserter-expander instrument is engaged with thesixteenth expandable fusion device 1000 t in a fully width expandedstate of the device, the device is then collapsed back to its initialstate for insertion into the disc space (best seen in FIG. 79A). Onceinserted into the disc-space, the bifurcated ramps of the instrument arepulled toward the proximate end of the device with the main body of theinstrument bearing against the proximal wedge and simultaneously turningthe actuator. This causes the sixteenth expandable fusion device 1000 tto expand in width up to an expansion width at which, the bifurcatedramps no longer make contact with the sixteenth expandable fusion device1000 t (state best seen in FIG. 79B) and are withdrawn. Once thathappens, the device is expanded in height. This arrangement means thatin order for the instrument 840 t to be disengaged from the sixteenthexpandable fusion device 1000 t, the device has to be sufficientlyexpanded in width to allow the front wedge to be withdrawn. Optionally,in any embodiment, multiple different front wedge widths may be suppliedto the end-user to allow them to make a determination of what targetexpansion width is best suited for a particular application. Due to thefact that the bifurcated ramps of the instrument have both front andrear contact surfaces with the endplates, the width expansion process isreversible in that if actuating the instrument in one direction willcause the device to expand in width, then reversing the direction ofactuation will cause the device to collapse in width.

Seventeenth Expandable Fusion Device

Now with reference to FIG. 80, FIG. 80 shows a diagram of general widthexpansion functionality of an exemplary seventeenth expandable fusiondevice 1000 u, which is identical to the thirteenth expandable fusiondevice 1000 p described above with certain exceptions described below.The seventeenth expandable fusion device 1000 u is a modification of thethirteenth expandable fusion device 1000 p where the generally parallelarticulating surfaces between the proximal wedge and its two matingramps and between the distal wedge and its two mating ramps are inclinedwith respect to the long axis of the device and possesses a desirableproperty of allowing the device to expand in width in a non-rectilinearfashion, causing the width expanded states of the device to have ageneral shape of a parallelogram instead of a rectangle produced by forexample the thirteenth expandable fusion device 1000 p. This is usefulfor some surgical approaches where the approach axis is angled withrespect to standard anatomical planes such as a transforaminal (or TLIF)approach.

Eighteenth Expandable Fusion Device

Provided herein, per FIGS. 81A-86, is an eighteenth expandable fusiondevice 1000 v for implantation between two adjacent vertebrae.Optionally, in any embodiment, per FIG. 81A the device 1000 v comprises:an actuator 500 v comprising a drive feature 503 v and an longitudinalaxis 504 v; a wedge assembly 750 v coupled to the actuator 500 v; a rampassembly 800 v slidably coupled with the wedge assembly 750 v; an upperendplate assembly 850 v slidably coupled with the ramp assembly 800 v;and a lower endplate assembly 900 v slidably coupled with the rampassembly 800 v.

Optionally, in any embodiment, per FIG. 81B, the device 1000 v has awidth 1100 v comprising an external width of at least one of the upperendplate assembly 850 v and the lower endplate assembly 900 v.Optionally, in any embodiment, the device has a height 1200 v comprisingan external distance between the upper endplate assembly 800 v and thelower endplate assembly 900 v.

Optionally, in any embodiment, per FIG. 81C, actuation of the drivefeature 503 v by a first number of actuations in a first actuationdirection 1300 v increases the width 1100 v without increasing theheight 1200 v. Optionally, in any embodiment, actuation of the drivefeature 503 v by a second number of actuations beyond the first numberof actuations in the first actuation direction 1300 v increases at leastone of the height 1200 v and the width 1100 v. Optionally, in anyembodiment, actuation of the drive feature 503 v by a second number ofactuations beyond the first number of actuations in the first actuationdirection 1300 v increases both the height 1200 v and the width 1100 v,wherein actuation of the drive feature 503 v by a third number ofactuations beyond the second number of actuations in the first actuationdirection 1300 v increases the height 1200 v without increasing thewidth 1100 v. Optionally, in any embodiment, actuation of the drivefeature 503 v by a second number of actuations beyond the first numberof actuations in the first actuation direction 1300 v increases neitherthe height 1200 v nor the width 1100 v, wherein actuation of the drivefeature 503 v by a third number of actuations beyond the second numberof actuations in the first actuation direction 1300 v increases theheight 1200 v without increasing the width 1100 v. Optionally, in anyembodiment, the width 1100 v of the device 1000 v reaches an apex oncethe drive feature 503 v is actuated by at least the first number ofactuations. Optionally, in any embodiment, the height 1200 v of thedevice 1000 v reaches an apex once the drive feature 503 v is actuatedby at least the first and second number of actuations.

Optionally, in any embodiment, actuation of the drive feature 503 v by asecond number of actuations beyond the first number of actuations in thefirst actuation direction 1300 v increases both the height 1200 v andthe width 1100 v. Optionally, in any embodiment, actuation of the drivefeature 503 v by a second number of actuations beyond the first numberof actuations in the first actuation direction increases the height 1200v without increasing the width 1100 v.

Optionally, in any embodiment, actuation of the drive feature 503 v inthe first actuation direction 1300 v by at least the first number ofactuations increases the height 1200 v of the device 1000 v by about 30%to about 400%. Optionally, in any embodiment, actuation of the drivefeature 503 v in the first actuation direction 1300 v by at least thefirst and the second number of actuations increases the width 1100 v ofthe device 1200 v by about 14% to about 150%.

Optionally, in any embodiment, per FIG. 82, the actuator 500 v comprisesa cylindrically shaped elongate shaft with a distal end and a proximalend. Optionally, in any embodiment, at least a portion of the distal endcomprises a first thread feature 501 v. Optionally, in any embodiment,at least a portion of the proximal end comprises a second thread feature502 v, and wherein the proximal end comprises the drive feature 503 v.Optionally, in any embodiment, at least one of the first thread feature501 v and the second thread feature 502 v comprise a thread disposedexternally around the actuator 500 v. Optionally, in any embodiment, thefirst thread feature 501 v and the second thread feature 502 v haveopposing threading directions. Optionally, in any embodiment, the firstthread feature 501 v and the second thread feature 502 v have the samethreading direction. Optionally, in any embodiment, at least one of thefirst thread feature 501 v and the second thread feature 502 v comprisesa right-handed threading. Optionally, in any embodiment, at least one ofthe first thread feature 501 v and the second thread feature 502 vcomprises a left-handed threading. Optionally, in any embodiment, thedrive feature 503 v comprises a recessed region configured to receive adriving instrument. Optionally, in any embodiment, the recessed regioncomprises a slot, Phillips, pozidrive, frearson, robertson, 12-pointflange, hex socket, security hex socket, star drive, security torx, ta,tri-point, tri-wing, spanner head, clutch, one-way, double-square,triple-square, polydrive, spline drive, double hex, bristol, or apentalobe recess or any other shaped recess. Optionally, in anyembodiment, the driving feature comprises a protuberance extendingtherefrom and configured to be coupled to a driving instrument.Optionally, in any embodiment, the protuberance comprises a hex, ahexalobular, or a square protuberance or any other shaped protuberance.Optionally, in any embodiment, the drive feature 503 v is coincidentwith the longitudinal axis 504 v.

Optionally, in any embodiment, per FIG. 81C, the wedge assemblycomprises a distal wedge 650 v and a proximal wedge 550 v. Optionally,in any embodiment, actuation of the drive feature in the first directionconverges the distal wedge 650 v and the proximal wedge 550 v toward oneanother. Optionally, in any embodiment, per FIG. 83A, the distal wedge650 v is an isosceles trapezoid prism comprising a distal face and aproximal face. Optionally, in any embodiment, the distal wedge 650 vcomprises a third thread feature 654 v. Optionally, in any embodiment,the third thread feature 654 v extends from the distal face of thedistal wedge 650 v, to the proximal face of the distal wedge 650 v.Optionally, in any embodiment, the distal wedge 650 v further comprisesone or more features configured for temporary attachment to an insertertool. Optionally, in any embodiment, the third thread feature 654 v isthreadably coupled to the second thread feature 502 v of the actuator500 v. Optionally, in any embodiment, the distal wedge 650 v furthercomprises first slot 651 v and second slot 652 v. Optionally, in anyembodiment, the first slot 651 v comprises an upper left first slot 651v, an upper right first slot 651 v, a lower left first slot 651 v, and alower right first slot 651 v. Optionally, in any embodiment, the upperleft first slot 651 v and the upper right first slot 651 v, and thelower left first slot 651 v and a lower right first slot 651 v havemirrored symmetry about a sagittal plane of the distal wedge 650 v.Optionally, in any embodiment, the upper left first slot 651 v and thelower left first slot 651 v, and the upper right first slot 651 v and alower right first slot 651 v have mirrored symmetry about a transverseplane of the distal wedge 650 v. Optionally, in any embodiment, themedial plane of each of the upper left first slot 651 v, the upper rightfirst slot 651 v, the lower left first slot 651 v, and the lower rightfirst slot 651 v are oriented at the transverse angle from the sagittalplane of the distal wedge 650 v. Optionally, in any embodiment, at leastone of the third thread feature 654 v and the fourth thread feature 554v in the distal wedge 650 v and the proximal wedge 550 v, respectively,comprise a thread locking feature configured to prevent actuation of atleast one of the third first feature 501 v and the second thread feature502 v of the actuator 500 v in a direction opposite the first actuationdirection 1300 v. Optionally, in any embodiment, the thread lockingfeature comprises a deformable insert, a deformable thread, a distortedthread, a flexible lip, or any combination thereof. Optionally, in anyembodiment, the thread locking feature comprises a bore within at leastone of the distal wedge 650 v and the proximal wedge 550 v configured toprovide access to the third thread feature 654 v or the fourth threadfeature 554 v, and/or which is configured to receive an insert such as apin, a screw, a dowel, a nut, or any combination thereof to preventactuation of the actuator 500 v.

Optionally, in any embodiment, the second slot 652 v comprises an upperleft second slot 652 v, an upper right second slot 652 v, a lower leftsecond slot 652 v, and a lower right second slot 652 v. Optionally, inany embodiment, the upper left second slot 652 v and the upper rightsecond slot 652 v, and the lower left second slot 652 v and a lowerright second slot 652 v have mirrored symmetry about a sagittal plane ofthe distal wedge 650 v. Optionally, in any embodiment, the upper leftsecond slot 652 v and the lower left second slot 652 v, and the upperright second slot 652 v and a lower right second slot 652 v havemirrored symmetry about a transverse plane of the distal wedge 650 v.Optionally, in any embodiment, the medial plane of the upper left secondslot 652 v, the upper right second slot 652 v, the lower left secondslot 652 v, and the lower right second slot 652 v are oriented at thetransverse angle from the sagittal plane of the distal wedge 650 v.

Optionally, in any embodiment, per FIG. 83B, the proximal wedge 550 vhas an isosceles trapezoid prism shape comprising a distal face and aproximal face. Optionally, in any embodiment, the proximal wedge 550 vcomprises a fourth thread feature 554 v. Optionally, in any embodiment,the fourth thread feature 554 v extends from the distal face of theproximal wedge 550 v, to the proximal face of the proximal wedge 550 v.Optionally, in any embodiment, the proximal wedge 550 v furthercomprises one or more features configured for temporary attachment to aninserter tool. Optionally, in any embodiment, the fourth thread feature554 v is threadably coupled to the first thread feature 501 v of theactuator 500 v. Optionally, in any embodiment, the third thread feature654 v comprises a thread disposed internally within the distal wedge 650v. Optionally, in any embodiment, the fourth thread feature 554 vcomprises a thread disposed internally within the proximal wedge 650 v.Optionally, in any embodiment, the third thread feature 654 v and thefourth thread feature 554 v have opposing threading directions.Optionally, in any embodiment, the third thread feature 654 v and thefourth thread feature 554 v have the same threading direction.Optionally, in any embodiment, at least one of the third thread feature654 v and the fourth thread feature 554 v comprises a right-handedthreading. Optionally, in any embodiment, at least one of the thirdthread feature 654 v and the fourth thread feature 554 v comprises aleft-handed threading.

Optionally, in any embodiment, per FIG. 81C, the ramp assembly 800 vcomprises a first proximal ramp 300 v, a second proximal ramp 400 v, afirst distal ramp 350 v, and a second distal ramp 450 v.

Optionally, in any embodiment, per FIGS. 84A and 84B, the second distalramp 400 v comprises a rectangular prism divided into two lobes.Optionally, in any embodiment, the second distal ramp 400 v comprises afirst ridge 401 v, a first protrusion 402 v, a v-slot 403 v, a thirdprotrusion 404 v, a third ridge 405 v, and a third slot 406 v.Optionally, in any embodiment, the first ridge 401 v comprises two firstridges 401 v. Optionally, in any embodiment, the first ridge 401 v islocated on the proximal end of the second distal ramp 400 v. Optionally,in any embodiment, the medial plane of the first ridge 401 v lies at thetraverse angle from the medial face of the second distal ramp 400 v.Optionally, in any embodiment, the first protrusion 402 v comprises twofirst protrusions 402 v. Optionally, in any embodiment, the firstprotrusion 402 v is located on the mesial proximal corners of the seconddistal ramp 400 v. Optionally, in any embodiment, the v-slot 403 vcomprise two v-slots 403 v. Optionally, in any embodiment, the v-slot403 v is located on the mesial plane of the second distal ramp 400 v.Optionally, in any embodiment, the apex of the v-slot 403 v is orientedtowards the distal end of the second distal ramp 400 v. Optionally, inany embodiment, the protrusion 404 v comprises two protrusions 404 v.Optionally, in any embodiment, the protrusion 404 v is located on thelower face of the distal ramp 400 v. Optionally, in any embodiment, thethird ridge 405 v comprises two the third ridges 405 v. Optionally, inany embodiment, the third ridge 405 v is located on the upper surface ofthe second distal ramp 400 v. Optionally, in any embodiment, the medialplane of the third ridge 405 v is parallel to the mesial face of thesecond distal ramp 400 v. Optionally, in any embodiment, the third slot406 v comprises two third slot 406 v comprises two the two third slots406 v. Optionally, in any embodiment, the third slot 406 v is located onthe upper surface of the second distal ramp 400 v. Optionally, in anyembodiment, the medial plane of the third slot 406 v is parallel to themesial face of the distal ramp 400 v. Optionally, in any embodiment, thefirst distal ramp 300 v is a mirrored equivalent of the second distalramp 400 v. Optionally, in any embodiment, the first distal ramp 350 vcomprises a second ridge 351 v. Optionally, in any embodiment, thesecond ridge 351 v comprises two second ridges 351 v. Optionally, in anyembodiment, the second ridge 351 v is located on the lateral side of thefirst distal ramp 350 v. Optionally, in any embodiment, the first distalramp 350 v comprises a second protrusion 352 v. Optionally, in anyembodiment, the second protrusion 352 v comprises two second protrusions352 v. Optionally, in any embodiment, the second protrusion 352 v islocated on the lateral proximal end of the first distal ramp 350 v.Optionally, in any embodiment, the medial plane of the second protrusion352 v is perpendicular to the medial plane of the second ridge 351 v.Optionally, in any embodiment, the first distal ramp 350 v comprises atongue 353 v. Optionally, in any embodiment, the tongue 353 v extendsfrom the bottom of the distal ramp 350 v to the top of the distal ramp350 v along the lateral proximal edge of the distal ramp 350 v.Optionally, in any embodiment, the second distal ramp 450 v is amirrored equivalent of the first distal ramp 350 v. Optionally, in anyembodiment, the upper endplate assembly comprises a first endplate 100 vand a second endplate 250 v. Optionally, in any embodiment, the lowerendplate assembly comprises a third endplate 150 v and a fourth endplate200 v.

Optionally, in any embodiment, at least one of the first endplate 100 vand the second endplate 250 v, the third endplate 150 v and the fourthendplate 200 v, the first proximal ramp 300 v and the second proximalramp 400 v, and the first distal ramp 350 v and the second distal ramp450 v have mirrored equivalence. Optionally, in any embodiment, at leastone of the second endplate 250 v and the fourth endplate 200 v is largerthan at least one of the first endplate 100 v and the third endplate 150v. Optionally, in any embodiment, at least one of the exterior faces ofthe first end plate 100 v, the second endplate 250 v, the third endplate150 v, and the fourth endplate 200 v comprise a texture configured togrip the vertebrae. Optionally, in any embodiment, the texturingcomprises a tooth, a ridge, a roughened area, a metallic coating, aceramic coating, a keel, a spike, a projection, a groove, or anycombination thereof.

Optionally, in any embodiment, per FIGS. 81A and 81C, the slideablecoupling between at least one of the wedge assembly 750 v and the rampassembly 800 v, the ramp assembly 800 v and the upper endplate assembly850 v, and the ramp assembly 800 v and the lower endplate assembly 900 vis at a transverse angle from the longitudinal axis 504 v. Optionally,in any embodiment, the transverse angle is about 0 degrees to about 90degrees.

Optionally, in any embodiment, the slideable coupling between at leastone of the wedge assembly 750 v and the ramp assembly 800 v, the rampassembly 800 v and the upper endplate assembly 850 v, and the rampassembly 800 v and the lower endplate assembly 900 v comprises aprotrusion and a slot. Optionally, in any embodiment, the protrusionextends from at least one of the wedge assembly 750 v the ramp assembly800 v, the upper endplate assembly 850 v, and the lower endplateassembly 900 v. Optionally, in any embodiment, the slot is disposed inat least one of the wedge assembly 750 v the ramp assembly 800 v, theupper endplate assembly 850 v, and the lower endplate assembly 900 v.Optionally, in any embodiment, the protrusion comprises a pin 600, aridge, a dimple, a bolt, a screw, a bearing, or any combination thereof.Optionally, in any embodiment, the slot comprises a through slot, ablind slot, a t-slot, a v-slot, a groove, or any combination thereof.

Optionally, in any embodiment, per FIGS. 81A-86B, the slideable couplingbetween the wedge assembly 750 v and the ramp assembly comprises 800 vthe first slot 651 v and the second slot 652 v within the distal wedge650 v, the third slot 551 v and the fourth slot 552 v within theproximal wedge 550 v, a first protrusion 402 v and a first ridge 401 v,within the first proximal ramp 300 v and the second proximal ramp 400 v,and a second protrusion 352 v, a second ridge 351 v, and a tongue 353 vwithin the first distal ramp 350 v and the second distal ramp 450 v.Optionally, in any embodiment, the number of at least one of the firstslots 651 v, the second slots 652 v, the third slots 551 v, the fourthslots 552 v, the first protrusions 402 v, the first ridges 401 v, thesecond protrusions 352 v, and the second ridges 351 v is about 1, 2, 3,4 or more.

Optionally, in any embodiment, the slideable coupling between theproximal wedge 550 v and the first proximal ramp 300 v or the secondproximal ramp 400 v comprises a slideable coupling between the thirdslot 551 v and the first ridge 401 v, and a slideable coupling betweenthe fourth slot 552 v and the first protrusion 402 v.

Optionally, in any embodiment, the slideable coupling between the distalwedge 650 v and the first distal ramp 350 v or the second distal ramp450 v comprises a slideable coupling between a first slot 651 v and asecond ridge 351 v, a slideable coupling between a second slot 652 v anda second protrusion 352 v, or any combination thereof.

Optionally, in any embodiment, the second slot 652 v within distal wedge650 v comprises a first stop 653 v to prevent the first protrusion 402 vfrom exiting the second slot 652 v in one direction. Optionally, in anyembodiment, the fourth slot 552 v within the proximal wedge 550 vcomprises a second stop 553 v to prevent the first protrusion 402 v fromexiting the second slot 652 v in one direction.

Optionally, in any embodiment, the slideable coupling between the rampassembly 800 v and the upper endplate assembly 850 v or the lowerendplate assembly 900 v comprises a tongue 353 v within at least one offirst distal ramp 350 and the second distal ramp 450, and a v-slot 403v, a third protrusion 404 v, a third ridge 405 v, and a third slot 406 vwithin at least one of first proximal ramp 300 and the second proximalramp 400, and a dovetail slot 101 v, a fourth protrusion 102 v, a fourthslot 104 v, a fifth slot 103 v and a fourth ridge 105 v within at leastone of the first endplate 100 v, the second endplate 250 v, the thirdendplate 150 v and the fourth endplate 200 v.

Optionally, in any embodiment, the slideable coupling between the firstdistal ramp 350 v or the second distal ramp 450 v and the first endplate 100 v, the second endplate 250 v, the third endplate 150 v, or thefourth endplate 200 v comprises a slideable coupling between thedovetail slot 101 v and the tongue 353 v.

Optionally, in any embodiment, the slideable coupling between the firstproximal ramp 300 v or the second proximal ramp 400 v and the first endplate 100 v, the second endplate 250 v, the third endplate 150 v, or thefourth endplate 200 v comprises a slideable coupling between the v-slot403 v and the fourth protrusion 102 v, a slideable coupling between thethird protrusion 404 v and the fourth slot 104 v, a slideable couplingbetween the third ridge 405 v and the fifth slot 103 v, a slideablecoupling between the third slot 406 v and the fourth ridge 105 v, or anycombination thereof.

Optionally, in any embodiment, the fourth protrusion 102 v comprises afeature of the first end plate 100 v, the second endplate 250 v, thethird endplate 150 v, or the fourth endplate 200 v. Optionally, in anyembodiment, the fourth protrusion 102 v comprises a separate componentthat is firmly inserted into the first end plate 100 v, the secondendplate 250 v, the third endplate 150 v, or the fourth endplate 200 v.Optionally, in any embodiment, the fourth protrusion 102 v comprises thepin 600 v.

Optionally, in any embodiment, the slideable coupling between the wedgeassembly 750 v and at least one of the upper endplate assembly 850 v andlower endplate assembly 900 v comprises a slideable coupling between adistal chamfer 123 v and a proximal chamfer 121 v in at least one of thefirst end plate 100 v, the second endplate 250 v, the third endplate 150v, and the fourth endplate 200 v, and a guide surface 621 v 521 v in atleast one of the distal wedge 650 v and a proximal wedge 550 v.Optionally, in any embodiment, the slideable coupling between the wedgeassembly 750 v and at least one of the upper endplate assembly 850 v andlower endplate assembly 900 v prevents the height 1200 v of the devicefrom increasing until the width 1100 v of the device's 1000 v reachesits apex.

Optionally, in any embodiment, at least one of the actuator 500 v, thewedge assembly 750 v, the ramp assembly 8000 v, the upper endplateassembly 850 v, and the lower endplate assembly 900 v comprise titanium,cobalt, stainless steel, tantalum, platinum, PEEK, PEKK, carbon fiber,barium sulfate, hydroxyapatite, a ceramic, zirconium oxide, siliconnitride, carbon, bone graft, demineralized bone matrix product,synthetic bone substitute, a bone morphogenic agent, a bone growthinducing material, or any combination thereof.

Further provided herein, per FIG. 81A, is an expandable fusion systemfor implantation between two adjacent vertebrae, the system comprising acollapsing tool 5000 v and the eighteenth expandable fusion device 1000v. Optionally, in any embodiment, once the actuator 500 v is actuated byat least the first number and the second number of actuations in a firstactuation direction 1300 v, such that the width 1100 v and the height1200 v of the device 1000 v are at their apex, actuation of the actuator500 v in a direction opposite the first actuation direction 1300 v mayonly reduce the width 1100 v, without reducing the height 1200 v of thedevice 1000 v. Optionally, in any embodiment, a collapsing tool 5000 vmay be employed to allow the height 1200 v reduction without width 1100v reduction. Optionally, in any embodiment, the collapsing tool 5000 vcomprises a first prong 5001 v and a second prong 5001 v, wherein thefirst prong 5001 v is configured to be inserted between the proximalwedge 550 v and/or the distal wedge 650 v and the first proximal ramp300 v, and wherein the second prong 5002 v is configured to be insertedbetween the proximal wedge 550 v and/or the distal wedge 650 v and thesecond proximal ramp 400 v. Optionally, in any embodiment, the firstprong 5001 v and the second prong 5001 v have the same length.Optionally, in any embodiment, the first prong 5001 v and the secondprong 5001 v have different lengths. Optionally, in any embodiment, thefirst prong 5001 v and the second prong 5001 v have the same thickness.Optionally, in any embodiment, the first prong 5001 v and the secondprong 5001 v have different thicknesses.

Optionally, in any embodiment, the eighteenth expandable fusion device1000 v may further or alternatively include any features, components, orcharacteristics of any of the previously described expandable fusiondevice.

The numerical indicators for the components of the exemplary eighteenthexpandable fusion device are compiled in Table 1, below.

TABLE 1 100v First endplate 101v Dovetail slot 102v Fourth protrusion103v Fourth slot 104v Fifth slot 105v Fourth ridge 150v Third endplate200v Fourth endplate 250v Second endplate 300v First proximal ramp 350vFirst distal ramp 351v Second protrusion 352v Second ridge 353v Tongue400v Second proximal ramp 401v First ridge 402v First protrusion 403vV-slot 404v Third protrusion 405v Third ridge 406v Third slot 450vSecond distal ramp 500v Actuator 501v First thread feature 502v Secondthread feature 503v Drive feature 504v Longitudinal axis 550v Proximalwedge 551v Third slot 552v Fourth slot 553v Second Stop 554v Fourththread feature 600v Pin 650v Distal wedge 651v First slot 652v Secondslot 653v First Stop 654v Third thread feature 750v Wedge assembly 800vRamp assembly 850v Upper endplate assembly 900v Lower endplate assembly1000v Eighteenth Device 1100v Width 1200v Height 1300v Axis of actuation5000v InserterNineteenth Expandable Fusion Device

Provided herein, per FIGS. 87A-94D, is a nineteenth expandable fusiondevice 1000 w for implantation between two adjacent vertebrae.Optionally, in any embodiment, per FIG. 81A the device 1000 w comprises:an actuator 500 w comprising a drive feature 503 w and an longitudinalaxis 504 v; a wedge assembly 750 w coupled to the actuator 500 v; a rampassembly 800 w slidably coupled with the wedge assembly 750 v; an upperendplate assembly 850 w slidably coupled with the ramp assembly 800 v;and a lower endplate assembly 900 w slidably coupled with the rampassembly 800 w. Optionally, in any embodiment, the upper endplateassembly 850 w is further slidably coupled with the lower endplateassembly 900 w.

Optionally, in any embodiment, per FIG. 87A, the device 1000 w has awidth 1100 w comprising an external width of at least one of the upperendplate assembly 850 w and the lower endplate assembly 900 w.Optionally, in any embodiment, the device has a height 1200 w comprisingan external distance between the upper endplate assembly 800 w and thelower endplate assembly 900 w.

Optionally, in any embodiment, per FIG. 87C, actuation of the drivefeature 503 w by a first number of actuations in a first actuationdirection 1300 w increases the width 1100 w without increasing theheight 1200 w. Optionally, in any embodiment, actuation of the drivefeature 503 w by a second number of actuations beyond the first numberof actuations in the first actuation direction 1300 w increases theheight 1200 w without increasing the width 1100 w. Optionally, in anyembodiment, actuation of the drive feature 503 w by a second number ofactuations beyond the first number of actuations in the first actuationdirection 1300 w increases both the height 1200 w and the width 1100 w,wherein actuation of the drive feature 503 w by a third number ofactuations beyond the second number of actuations in the first actuationdirection 1300 w increases the height 1200 w without increasing thewidth 1100 v. Optionally, in any embodiment, actuation of the drivefeature 503 w by a second number of actuations beyond the first numberof actuations in the first actuation direction 1300 w increases neitherthe height 1200 w nor the width 1100 w, wherein actuation of the drivefeature 503 w by a third number of actuations beyond the second numberof actuations in the first actuation direction 1300 w increases theheight 1200 w without increasing the width 1100 w. Optionally, in anyembodiment, the width 1100 w of the device 1000 w reaches an apex oncethe drive feature 503 w is actuated by at least the first number ofactuations. Optionally, in any embodiment, the height 1200 w of thedevice 1000 w reaches an apex once the drive feature 503 w is actuatedby at least the first and second number of actuations.

Optionally, in any embodiment, actuation of the drive feature 503 w by asecond number of actuations beyond the first number of actuations in thefirst actuation direction 1300 w increases both the height 1200 w andthe width 1100 w. Optionally, in any embodiment, actuation of the drivefeature 503 w by a second number of actuations beyond the first numberof actuations in the first actuation direction increases the height 1200w without increasing the width 1100 w.

Optionally, in any embodiment, actuation of the drive feature 503 w inthe first actuation direction 1300 w by at least the first number ofactuations increases the height 1200 w of the device 1000 w by about 30%to about 400%. Optionally, in any embodiment, actuation of the drivefeature 503 w in the first actuation direction 1300 w by at least thefirst and the second number of actuations increases the width 1100 w ofthe device 1200 w by about 14% to about 150%.

Optionally, in any embodiment, per FIG. 88, the actuator 500 w comprisesa cylindrically shaped elongate shaft with a distal end and a proximalend. Optionally, in any embodiment, at least a portion of the distal endof the actuator 500 w comprises a first thread feature 501 w.Optionally, in any embodiment, at least a portion of the proximal end ofthe actuator 500 w comprises a second thread feature 502 w, and whereinthe proximal end comprises the drive feature 503 w. Optionally, in anyembodiment, at least one of the first thread feature 501 w and thesecond thread feature 502 w comprise a thread disposed externally aroundthe actuator 500 w. Optionally, in any embodiment, the first threadfeature 501 w and the second thread feature 502 w have opposingthreading directions. Optionally, in any embodiment, the first threadfeature 501 w and the second thread feature 502 w have the samethreading direction. Optionally, in any embodiment, at least one of thefirst thread feature 501 w and the second thread feature 502 w comprisesa right-handed threading. Optionally, in any embodiment, at least one ofthe first thread feature 501 w and the second thread feature 502 wcomprises a left-handed threading. Optionally, in any embodiment, thedrive feature 503 w comprises a recessed region configured to receive adriving instrument. Optionally, in any embodiment, the recessed regioncomprises a slot, Phillips, pozidrive, frearson, robertson, 12-pointflange, hex socket, security hex socket, star drive, security torx, ta,tri-point, tri-wing, spanner head, clutch, one-way, double-square,triple-square, polydrive, spline drive, double hex, bristol, or apentalobe recess. Optionally, in any embodiment, the driving featurecomprises a protuberance extending therefrom and configured to becoupled to a driving instrument. Optionally, in any embodiment, theprotuberance comprises a hex, a hexalobular, or a square protuberance.Optionally, in any embodiment, the drive feature 503 w is coincidentwith the longitudinal axis 504 w.

Optionally, in any embodiment, per FIG. 87C, the wedge assemblycomprises a distal wedge 650 w and a proximal wedge 550 w. Optionally,in any embodiment, actuation of the drive feature in the first directionconverges the distal wedge 650 w and the proximal wedge 550 w toward oneanother. Optionally, in any embodiment, per FIG. 89A-B, the distal wedge650 w is a crescent-shaped prism comprising a distal end, a proximalend, a top side, and a bottom side. Optionally, in any embodiment, thedistal wedge 650 w comprises a third thread feature 654 w. Optionally,in any embodiment, the third thread feature 654 w extends from thedistal end of the distal wedge 650 w, to the proximal end of the distalwedge 650 w. Optionally, in any embodiment, the distal wedge 650 wfurther comprises one or more features configured for temporaryattachment to an inserter tool. Optionally, in any embodiment, the thirdthread feature 654 w is threadably coupled to the second thread feature502 w of the actuator 500 w. Optionally, in any embodiment, the distalwedge 650 w further comprises first slot 651 w and second slot 652 w.Optionally, in any embodiment, the first slot 651 w comprises an upperleft first slot 651 w, an upper right first slot 651 w, a lower leftfirst slot 651 w, and a lower right first slot 651 w. Optionally, in anyembodiment, the upper left first slot 651 w and the lower left firstslot 651 w, and the upper right first slot 651 w and a lower right firstslot 651 w have mirrored symmetry about a transverse plane of the distalwedge 650 w. Optionally, in any embodiment, the medial plane of each ofthe upper left first slot 651 w, the upper right first slot 651 w, thelower left first slot 651 w, and the lower right first slot 651 w areoriented at the transverse angle from the sagittal plane of the distalwedge 650 w. Optionally, in any embodiment, the second slot 652 wcomprises an upper left second slot 652 w, an upper right second slot652 w, a lower left second slot 652 w, and a lower right second slot 652w. Optionally, in any embodiment, the upper left second slot 652 w andthe lower left second slot 652 w, and the upper right second slot 652 wand a lower right second slot 652 w have mirrored symmetry about atransverse plane of the distal wedge 650 w. Optionally, in anyembodiment, the medial plane of the upper left second slot 652 w, theupper right second slot 652 w, the lower left second slot 652 w, and thelower right second slot 652 w are oriented at the transverse angle fromthe sagittal plane of the distal wedge 650 w. Optionally, in anyembodiment, the proximal wedge 550 w is equivalent to the distal wedge650 w. Optionally, in any embodiment, per FIG. 87C, the sagittal planeof the distal wedge 650 w is arranged to be coplanar with the sagittalplane of the proximal wedge 550 w. Optionally, in any embodiment, perFIG. 87C, the sagittal plane of the distal wedge 650 w is arranged to bearranged 180 degrees from the sagittal plane of the proximal wedge 550w.

Optionally, in any embodiment, at least one of the third thread feature654 w and the fourth thread feature 554 w in the distal wedge 650 w andthe proximal wedge 550 w, respectively, comprise a thread lockingfeature configured to prevent actuation of at least one of the thirdfirst feature 501 w and the second thread feature 502 w of the actuator500 w in a direction opposite the first actuation direction 1300 w.Optionally, in any embodiment, the thread locking feature comprises adeformable insert, a deformable thread, a distorted thread, a flexiblelip, or any combination thereof. Optionally, in any embodiment, thethread locking feature comprises a bore within at least one of thedistal wedge 650 w and the proximal wedge 550 w configured to provideaccess to the third thread feature 654 w or the fourth thread feature554 w, and/or which is configured to receive an insert such as a pin, ascrew, a dowel, a nut, or any combination thereof to prevent actuationof the actuator 500 w. Optionally, in any embodiment, per FIG. 87C, theramp assembly 800 w comprises a first proximal ramp 300 w, a secondproximal ramp 400 w, a first distal ramp 350 w, and a second distal ramp450 w.

Optionally, in any embodiment, per FIGS. 90A and 90B, the secondproximal ramp 400 w generally comprises a triangular prism. Optionally,in any embodiment, the second proximal ramp 400 w comprises a firstridge 401 w, a first protrusion 402 w, a v-slot 403 w, a thirdprotrusion 404 w, a third ridge 405 w, and a third slot 406 w.Optionally, in any embodiment, the first ridge 401 w comprises two firstridges 401 w. Optionally, in any embodiment, the medial plane of thefirst ridge 401 w lies at the traverse angle from the medial face of thesecond proximal ramp 400 w. Optionally, in any embodiment, the firstprotrusion 402 w comprises two first protrusions 402 w. Optionally, inany embodiment, the v-slot 403 w is located on the transverse plane ofthe second proximal ramp 400 w. Optionally, in any embodiment, the apexof the v-slot 403 w is oriented towards the mesial plane of the device1000 w. Optionally, in any embodiment, the protrusion 404 w comprisestwo protrusions 404 w. Optionally, in any embodiment, the protrusion 404w is located on the lower face of the distal ramp 400 w. Optionally, inany embodiment, the third ridge 405 w comprises two the third ridges 405w. Optionally, in any embodiment, the third ridge 405 w is located onthe lower surface of the second proximal ramp 400 w. Optionally, in anyembodiment, the medial plane of the third ridge 405 w is parallel to themesial face of the second proximal ramp 400 w. Optionally, in anyembodiment, the third slot 406 w comprises two third slot 406 wcomprises two the two third slots 406 w. Optionally, in any embodiment,the third slot 406 w is located on the upper surface of the secondproximal ramp 400 w. Optionally, in any embodiment, the medial plane ofthe third slot 406 w is parallel to the mesial face of the distal ramp400 w. Optionally, in any embodiment, the second proximal ramp 300 w isequivalent to the first distal ramp 350 w.

Optionally, in any embodiment, per FIGS. 91A and 91B, the first proximalramp 300 w generally comprises a triangular prism. Optionally, in anyembodiment, the second distal ramp 300 w comprises a first ridge 301 w,a first protrusion 302 w, a v-slot 303 w, a third protrusion 304 w, athird ridge 305 w, and a third slot 306 w. Optionally, in anyembodiment, the first ridge 301 w comprises two first ridges 301 w.Optionally, in any embodiment, the medial plane of the first ridge 301 wlies at the traverse angle from the medial face of the second distalramp 300 w. Optionally, in any embodiment, the first protrusion 302 wcomprises two first protrusions 302 w. Optionally, in any embodiment,the v-slot 303 w is located on the transverse plane of the second distalramp 300 w. Optionally, in any embodiment, the apex of the v-slot 303 wis oriented towards the mesial plane of the device 1000 w. Optionally,in any embodiment, the protrusion 304 w comprises two protrusions 304 w.Optionally, in any embodiment, the protrusion 304 w is located on thelower face of the distal ramp 300 w. Optionally, in any embodiment, thethird ridge 305 w comprises two the third ridges 305 w. Optionally, inany embodiment, the third ridge 305 w is located on the lower surface ofthe second distal ramp 300 w. Optionally, in any embodiment, the medialplane of the third ridge 305 w is parallel to the mesial face of thesecond distal ramp 300 w. Optionally, in any embodiment, the third slot306 w comprises two third slot 306 w comprises two the two third slots306 w. Optionally, in any embodiment, the third slot 306 w is located onthe upper surface of the second distal ramp 300 w. Optionally, in anyembodiment, the medial plane of the third slot 306 w is parallel to themesial face of the distal ramp 300 w. Optionally, in any embodiment, thefirst proximal ramp 300 w is equivalent to the second distal ramp 450 w.

Optionally, in any embodiment, the upper endplate assembly comprises afirst endplate 100 w and a second endplate 250 w. Optionally, in anyembodiment, the lower endplate assembly comprises a third endplate 150 wand a fourth endplate 200 w.

Optionally, in any embodiment, at least one of the first endplate 100 wand the second endplate 250 w, the third endplate 150 w and the fourthendplate 200 w, the first proximal ramp 300 w and the second proximalramp 400 w, and the first distal ramp 350 w and the second distal ramp450 w have mirrored equivalence. Optionally, in any embodiment, at leastone of the second endplate 250 w and the fourth endplate 200 w is largerthan at least one of the first endplate 100 w and the third endplate 150w. Optionally, in any embodiment, at least one of the exterior faces ofthe first end plate 100 w, the second endplate 250 w, the third endplate150 w, and the fourth endplate 200 w comprise a texture configured togrip the vertebrae. Optionally, in any embodiment, the texturingcomprises a tooth, a ridge, a roughened area, a metallic coating, aceramic coating, a keel, a spike, a projection, a groove, or anycombination thereof.

Optionally, in any embodiment, per FIGS. 87A and 87C, the slideablecoupling between at least one of the wedge assembly 750 w and the rampassembly 800 w, the ramp assembly 800 w and the upper endplate assembly850 w, and the ramp assembly 800 w and the lower endplate assembly 900 wis at a transverse angle from the longitudinal axis 504 w. Optionally,in any embodiment, the transverse angle is about 0 degrees to about 90degrees.

Optionally, in any embodiment, the slideable coupling between at leastone of the wedge assembly 750 w and the ramp assembly 800 w, the rampassembly 800 w and the upper endplate assembly 850 w, and the rampassembly 800 w and the lower endplate assembly 900 w comprises aprotrusion and a slot. Optionally, in any embodiment, the protrusionextends from at least one of the wedge assembly 750 w the ramp assembly800 w, the upper endplate assembly 850 w, and the lower endplateassembly 900 w. Optionally, in any embodiment, the slot is disposed inat least one of the wedge assembly 750 w the ramp assembly 800 w, theupper endplate assembly 850 w, and the lower endplate assembly 900 w.Optionally, in any embodiment, the protrusion comprises a pin 600, aridge, a dimple, a bolt, a screw, a bearing, or any combination thereof.Optionally, in any embodiment, the slot comprises a through slot, ablind slot, a t-slot, a v-slot, a groove, or any combination thereof.

Optionally, in any embodiment, per FIGS. 87A-95B, the slideable couplingbetween the wedge assembly 750 w and the ramp assembly comprises 800 wthe first slot 651 w and the second slot 652 w within the distal wedge650 w, the third slot 551 w and the fourth slot 552 w within theproximal wedge 550 w, a first protrusion 402 w and a first ridge 401 w,within the first proximal ramp 300 w and the second proximal ramp 400 w,and a second protrusion 352 w, a second ridge 351 w, and a v-slot 353 wwithin the first distal ramp 350 w and the second distal ramp 450 w.Optionally, in any embodiment, the number of at least one of the firstslots 651 w, the second slots 652 w, the third slots 551 w, the fourthslots 552 w, the first protrusions 402 w, the first ridges 401 w, thesecond protrusions 352 w, and the second ridges 351 w is about 1, 2, 3,4 or more.

Optionally, in any embodiment, the slideable coupling between theproximal wedge 550 w and the first proximal ramp 300 w or the secondproximal ramp 400 w comprises a slideable coupling between the thirdslot 551 w and the first ridge 401 w, and a slideable coupling betweenthe fourth slot 552 w and the first protrusion 402 w.

Optionally, in any embodiment, the slideable coupling between the distalwedge 650 w and the first distal ramp 350 w or the second distal ramp450 w comprises a slideable coupling between a first slot 651 w and asecond ridge 351 w, a slideable coupling between a second slot 652 w anda second protrusion 352 w, or any combination thereof.

Optionally, in any embodiment, the second slot 652 w within distal wedge650 w comprises a first stop 653 w to prevent the first protrusion 402 wfrom exiting the second slot 652 w in one direction. Optionally, in anyembodiment, the fourth slot 552 w within the proximal wedge 550 wcomprises a second stop 553 w to prevent the first protrusion 402 w fromexiting the second slot 652 w in one direction.

Optionally, in any embodiment, the slideable coupling between the rampassembly 800 w and the upper endplate assembly 850 w or the lowerendplate assembly 900 w comprises a tongue 353 w within at least one offirst distal ramp 350 and the second distal ramp 450, and a v-slot 403w, a third protrusion 404 w, a third ridge 405 w, and a third slot 406 wwithin at least one of first proximal ramp 300 and the second proximalramp 400, and a dovetail slot 101 w 151 w 201 w 251 w, a fourthprotrusion 102 w 152 w 202 w 252 w, a fifth slot 103 w 153 w 203 w 253w, a fourth slot 104 w 154 w 204 w 254 w and a fourth ridge 105 w 155 w205 w 255 w within at least one of the first endplate 100 w, the secondendplate 250 w, the third endplate 150 w and the fourth endplate 200 w.

Optionally, in any embodiment, the slideable coupling between the firstdistal ramp 350 w or the second distal ramp 450 w and the first endplate 100 w, the second endplate 250 w, the third endplate 150 w, or thefourth endplate 200 w comprises a slideable coupling between thedovetail slot 101 w 151 w 201 w 251 w and the tongue 353 w.

Optionally, in any embodiment, the slideable coupling between the firstproximal ramp 300 w or the second proximal ramp 400 w and the first endplate 100 w, the second endplate 250 w, the third endplate 150 w, or thefourth endplate 200 w comprises a slideable coupling between the v-slot403 w and the fourth protrusion 102 w 152 w 202 w 252 w, a slideablecoupling between the third protrusion 404 w and the fourth slot 104 w154 w 204 w 254 w, a slideable coupling between the third ridge 405 wand the fifth slot 103 w 153 w 203 w 253 w, a slideable coupling betweenthe third slot 406 w and the fourth ridge 105 w 155 w 205 w 255 w, orany combination thereof.

Optionally, in any embodiment, the fourth protrusion 102 w 152 w 202 w252 w comprises a feature of the first end plate 100 w, the secondendplate 250 w, the third endplate 150 w, or the fourth endplate 200 w.Optionally, in any embodiment, the fourth protrusion 102 w 152 w 202 w252 w comprises a separate component that is firmly inserted into thefirst end plate 100 w, the second endplate 250 w, the third endplate 150w, or the fourth endplate 200 w. Optionally, in any embodiment, thefourth protrusion 102 w 152 w 202 w 252 w comprises the pin 600 w.

Optionally, in any embodiment, the slideable coupling between the upperendplate assembly 850 w and the lower endplate assembly 900 w comprisesa slideable coupling between a tongue 101 w in the first endplate 100 wand a groove 151 w in the third endplate 150 w, and a slideable couplingbetween a tongue 251 w in the second endplate 250 w and a groove 201 win the fourth endplate 200 w.

Optionally, in any embodiment, the slideable coupling between the wedgeassembly 750 w and at least one of the upper endplate assembly 850 w andlower endplate assembly 900 w comprises a slideable coupling between adistal chamfer 123 w and a proximal chamfer 121 w in at least one of thefirst end plate 100 w, the second endplate 250 w, the third endplate 150w, and the fourth endplate 200 w, and a guide surface 621 w 521 w in atleast one of the distal wedge 650 w and a proximal wedge 550 w.Optionally, in any embodiment, the slideable coupling between the wedgeassembly 750 w and at least one of the upper endplate assembly 850 w andlower endplate assembly 900 w prevents the height 1200 w of the devicefrom increasing until the width 1100 w of the device's 1000 w reachesits apex.

Optionally, in any embodiment, at least one of the actuator 500 w, thewedge assembly 750 w, the ramp assembly 8000 w, the upper endplateassembly 850 w, and the lower endplate assembly 900 w comprise titanium,cobalt, stainless steel, tantalum, platinum, PEEK, PEKK, carbon fiber,barium sulfate, hydroxyapatite, a ceramic, zirconium oxide, siliconnitride, carbon, bone graft, demineralized bone matrix product,synthetic bone substitute, a bone morphogenic agent, a bone growthinducing material, or any combination thereof.

Optionally, in any embodiment, the nineteenth expandable fusion device1000W may further or alternatively include any features, components, orcharacteristics of any of the previously described expandable fusiondevice.

Further provided herein, per FIGS. 96A to 97, is an expandable fusionsystem for implantation between two adjacent vertebrae, the systemcomprising a collapsing tool 5000 w and the nineteenth expandable fusiondevice 1000 v. Optionally, in any embodiment, once the actuator 500 w isactuated by at least the first number and the second number ofactuations in a first actuation direction 1300 w such that the width1100 w and the height 1200 w of the device 1000 w are at their apex,actuation of the actuator 500 w in a direction opposite the firstactuation direction 1300 w may only reduce the width 1100 w, withoutreducing the height 1200 w of the device 1000 v. Optionally, in anyembodiment, a collapsing tool 5000 w may be employed to allow the height1200 w reduction without width 1100 w reduction. Optionally, in anyembodiment, the collapsing tool 5000 w comprises a first prong 5001 wand a second prong 5001 w, wherein the first prong 5001 w is configuredto be inserted between the proximal wedge 550 w and/or the distal wedge650 w and the first proximal ramp 300 w, and wherein the second prong5002 w is configured to be inserted between the proximal wedge 550 wand/or the distal wedge 650 w and the second proximal ramp 400 w.Optionally, in any embodiment, the first prong 5001 w and the secondprong 5001 w have the same length. Optionally, in any embodiment, thefirst prong 5001 w and the second prong 5001 w have different lengths.Optionally, in any embodiment, the first prong 5001 w and the secondprong 5001 w have the same thickness. Optionally, in any embodiment, thefirst prong 5001 w and the second prong 5001 w have differentthicknesses.

The numerical indicators for the components of the exemplary nineteenthexpandable fusion device are compiled in Table 2, below.

TABLE 2 100w First endplate 101w Dovetail slot 102w Fourth protrusion103w Fourth slot 104w Fifth slot 105w Fourth ridge 150w Third endplate200w Fourth endplate 250w Second endplate 300w First proximal ramp 350wFirst distal ramp 351w Second protrusion 352w Second ridge 353w Tongue400w Second proximal ramp 401w First ridge 402w First protrusion 403wV-slot 404w Third protrusion 405w Third ridge 406w Third slot 450wSecond distal ramp 500w Actuator 501w First thread feature 502w Secondthread feature 503w Drive feature 504w Longitudinal axis 550w Proximalwedge 551w Third slot 552w Fourth slot 553w Second Stop 554w Fourththread feature 600w Pin 650w Distal wedge 651w First slot 652w Secondslot 653w First Stop 654w Third thread feature 750w Wedge assembly 800wRamp assembly 850w Upper endplate assembly 900w Lower endplate assembly1000w Eighteenth Device 1100w Width 1200w Height 1300w Axis of actuation5000w InserterTwentieth Expandable Fusion Device

Provided herein, per FIGS. 98A-B, is a twentieth expandable fusiondevice 1000 x for implantation between two adjacent vertebrae.Optionally, in any embodiment, per FIG. 95a the device 1000 x comprises:an actuator 500 x comprising a drive feature 503 x and an longitudinalaxis 504 x; a wedge assembly 750 x coupled to the actuator 500 x; a rampassembly 800 x slidably coupled with the wedge assembly 750 x; an upperendplate assembly 850 x slidably coupled with the ramp assembly 800 x;and a lower endplate assembly 900 x slidably coupled with the rampassembly 800 w.

Optionally, in any embodiment, at least one of the actuator 500 w, thewedge assembly 750 x, the ramp assembly 8000 x, the upper endplateassembly 850 x, and the lower endplate assembly 900 x comprise titanium,cobalt, stainless steel, tantalum, platinum, PEEK, PEKK, carbon fiber,barium sulfate, hydroxyapatite, a ceramic, zirconium oxide, siliconnitride, carbon, bone graft, demineralized bone matrix product,synthetic bone substitute, a bone morphogenic agent, a bone growthinducing material, or any combination thereof.

Optionally, in any embodiment, the twentieth expandable fusion device1000 x can further or alternatively include any features, components, orcharacteristics of any of the previously described expandable fusiondevice.

Twenty-First Expandable Fusion Device

Provided herein, per FIG. 99, is a twenty-first expandable fusion device1000 y for implantation between two adjacent vertebrae. Optionally, inany embodiment, per FIG. 95a the device comprises: an actuatorcomprising a drive feature and an longitudinal axis; a wedge assemblycoupled to the actuator; a ramp assembly slidably coupled with the wedgeassembly; an upper endplate assembly slidably coupled with the rampassembly; and a lower endplate assembly slidably coupled with the rampassembly. Optionally, in any embodiment, the twenty-first expandablefusion device 1000 y comprises a gap 101 y between at least one of theupper endplate assembly and the lower endplate assembly, and at leastone of the proximal wedge and the distal wedge. Optionally, in anyembodiment, the gap 101 y enables the device 1000 y to expand in widthand height simultaneously.

Optionally, in any embodiment, at least one of the actuator, the wedgeassembly, the ramp assembly, the upper endplate assembly, and the lowerendplate assembly comprise titanium, cobalt, stainless steel, tantalum,platinum, PEEK, PEKK, carbon fiber, barium sulfate, hydroxyapatite, aceramic, zirconium oxide, silicon nitride, carbon, bone graft,demineralized bone matrix product, synthetic bone substitute, a bonemorphogenic agent, a bone growth inducing material, or any combinationthereof.

Optionally, in any embodiment, the lack of a slideable coupling betweenthe wedge assembly and at least one of the upper endplate assembly andlower endplate assembly allows both the height and width of the device1000 y to increase until their relative apexes. Optionally, in anyembodiment, the height and width of the 1000 y increase at the same ratewhen the actuator is actuated in a first direction.

Optionally, in any embodiment, actuation of the drive feature by firstnumber of actuations in the first actuation direction increases both theheight and the width of the device 1000 x at the same rate. Optionally,in any embodiment, actuation of the drive feature by first number ofactuations in the first actuation direction increases both the heightand the width of the device 1000 x at different rates.

Optionally, in any embodiment, the twentieth expandable fusion device1000 x can further or alternatively include any features, components, orcharacteristics of any of the previously described expandable fusiondevice.

Terms and Definitions

Unless otherwise defined, all technical terms used herein have the samemeaning as commonly understood by one of ordinary skill in the art towhich this disclosure belongs.

As used herein, the singular forms “a,” “an,” and “the” include pluralreferences unless the context clearly dictates otherwise. Any referenceto “or” herein is intended to encompass “and/or” unless otherwisestated.

As used herein, the term “about” refers to an amount that is near thestated amount by 10%, 5%, or 1%, including increments therein.

As used herein, the term “longitudinal axis” refers to a theoreticalaxis in space comprising an axis of revolving symmetry of an object.

As used herein, the term “slidably coupled” refers to a relationshipbetween two or more components whereby the components share at least onedegree of freedom.

As used herein, the term “external width” refers to the width betweenthe outermost surfaces of an object.

As used herein, the term “external distance” refers to the distancebetween the outermost surfaces of an object.

As used herein, the term “apex” refers to the maximum value of adistance, measurement, or parameter.

As used herein, the term “thread feature” refers to one or more helicalor spiral protrusions or recesses capable of acting as, or coupling withanother thread feature.

What is claimed is:
 1. An expandable fusion device for implantationbetween two adjacent vertebrae, the device comprising: an actuatorcomprising a drive feature and a longitudinal axis; a wedge assemblycoupled to the actuator, the wedge assembly providing a width expansionof the device; a ramp assembly slidably coupled with the wedge assembly,the ramp assembly providing a height expansion of the device; an upperendplate assembly slidably coupled with the ramp assembly; and, a lowerendplate assembly slidably coupled with the ramp assembly; wherein, thedevice has a width comprising an external width of at least one of theupper endplate assembly and the lower endplate assembly; wherein, thedevice has a height comprising an external distance between the upperendplate assembly and the lower endplate assembly; wherein, actuation ofthe drive feature by a first number of actuations in a first actuationdirection increases the width without increasing the height; and,wherein, actuation of the drive feature by a second number of actuationsbeyond the first number of actuations in the first actuation directionincreases both the height and the width.
 2. The device of claim 1,wherein the wedge assembly comprises a distal wedge and a proximalwedge.
 3. The device of claim 1, wherein the ramp assembly comprises afirst distal ramp, a second distal ramp, a first proximal ramp, and asecond proximal ramp.
 4. The device of claim 1, wherein the slideablecoupling between at least one of the wedge assembly and the rampassembly, the ramp assembly and the upper endplate, assembly, and theramp assembly and the lower endplate assembly is at a transverse anglefrom the longitudinal axis.
 5. The device of claim 1, wherein the upperendplate assembly comprises a first endplate and a second endplate, andwherein the lower endplate assembly comprises a third endplate and afourth endplate.
 6. The device of claim 5, wherein the ramp assemblycomprises a first proximal ramp and a second proximal ramp, and a firstdistal ramp and a second distal ramp, and wherein at least one of thefirst endplate and the second endplate, the third endplate and thefourth endplate, the first proximal ramp and the second proximal ramp,and the first distal ramp and the second distal ramp have mirroredequivalence.
 7. The device of claim 5, wherein at least one of thesecond endplate and the fourth endplate is larger than at least one ofthe first endplate and the third endplate.
 8. An expandable fusionsystem for implantation between two adjacent vertebrae, the systemcomprising an inserter and the expandable fusion device of claim
 1. 9.The system of claim 8 further comprising a collapsing tool.
 10. Anexpandable fusion device for implantation between two adjacentvertebrae, the device comprising: an actuator comprising a drive featureand a longitudinal axis; a wedge assembly coupled to the actuator, thewedge assembly providing a width expansion of the device; a rampassembly slidably coupled with the wedge assembly, the ramp assemblyproviding a height expansion of the device; an upper endplate assemblyslidably coupled with the ramp assembly; and, a lower endplate assemblyslidably coupled with the ramp assembly; wherein, the device has a widthcomprising an external width of at least one of the upper endplateassembly and the lower endplate assembly; wherein, the device has aheight comprising an external distance between the upper endplateassembly and the lower endplate assembly; wherein, actuation of thedrive feature by a first number of actuations in a first actuationdirection increases the width without increasing the height; wherein,actuation of the drive feature by a second number of actuations beyondthe first number of actuations in the first actuation directionincreases at least one of the height and the width; and wherein,actuation of the drive feature by a third number of actuations beyondthe first and second number of actuations in the first actuationdirection increases the height without increasing the width.
 11. Thedevice of claim 10, wherein the width of the device reaches an apex oncethe drive feature is actuated by at least the first number ofactuations.
 12. The device of claim 10, wherein the height of the devicereaches an apex once the drive feature is actuated by at least the firstand second number of actuations.
 13. The device of claim 11, whereinactuation of the drive feature in the first actuation direction by atleast the first number of actuations increases the height of the deviceby at most 400%.
 14. The device of claim 12, wherein actuation of thedrive feature in the first actuation direction by at least the first andthe second number of actuations increases the width of the device by atmost 150%.
 15. The device of claim 10, wherein the actuator has a distalend and a proximal end, wherein at least a portion of the distal endcomprises a first thread feature, wherein at least a portion of theproximal end comprises a second thread feature, and wherein the proximalend comprises the drive feature.
 16. The device of claim 15, wherein atleast one of the first thread feature and the second thread featurecomprise a thread disposed externally around the actuator.
 17. Thedevice of claim 15, wherein the first thread feature and the secondthread feature have an opposite threading direction.
 18. The device ofclaim 10, wherein the wedge assembly comprises a distal wedge and aproximal wedge.
 19. The device of claim 18, wherein actuation of thedrive feature in the first direction converges the distal wedge and theproximal wedge toward one another.
 20. The device of claim 18, whereinthe actuator has a distal end and a proximal end, wherein at least aportion of the distal end comprises a first thread feature, wherein atleast a portion of the proximal end comprises a second thread feature,and wherein the proximal end comprises the drive feature; and, thedistal wedge comprises a third thread feature, and wherein the thirdthread feature is threadably coupled to the first thread feature. 21.The device of claim 20, wherein the proximal wedge comprises a fourththread feature, and wherein the fourth thread feature is threadablycoupled to the second thread feature.
 22. The device of claim 21,wherein the third thread feature comprises a thread disposed internallywithin the distal wedge.
 23. The device of claim 21, wherein the fourththread feature comprises a thread disposed internally within theproximal wedge.
 24. The device of claim 18, wherein the slideablecoupling between at least one of the wedge assembly and the rampassembly, the ramp assembly and the upper endplate, assembly, and theramp assembly and the lower endplate assembly is at a transverse anglefrom the longitudinal axis.
 25. The device of claim 24, wherein thetransverse angle is 0 degrees to 90 degrees.
 26. The device of claim 10,wherein the ramp assembly comprises a first distal ramp, a second distalramp, a first proximal ramp, and a second proximal ramp.
 27. The deviceof claim 10, wherein the slideable coupling between at least one of thewedge assembly and the ramp assembly, the ramp assembly and the upperendplate, assembly, and the ramp assembly and the lower endplateassembly comprises a protrusion and a slot, wherein the protrusionextends from at least one of the wedge assembly, the ramp assembly, theupper endplate assembly, and the lower endplate assembly, and whereinthe slot is disposed in at least one of the upper endplate assembly, andthe lower endplate assembly.
 28. The device of claim 27, wherein theprotrusion comprises a pin, a ridge, a dimple, a bolt, a screw, abearing, or any combination thereof.
 29. The device of claim 27, whereinthe slot comprises a through slot, a blind slot, a t-slot, a v-slot, agroove, or any combination thereof.
 30. The device of claim 10, whereinthe drive feature comprises a recessed region configured to receive adriving instrument.
 31. The device of claim 30, wherein the recessedregion comprises a slot, Phillips, pozidrive, frearson, robertson,12-point flange, hex socket, security hex socket, star drive, securitytorx, ta, tri-point, tri-wing, spanner head, clutch, one-way,double-square, triple-square, polydrive, spline drive, double hex,bristol, a thread, a friction fit, or a pentalobe recess.
 32. The deviceof claim 10, wherein the drive feature comprises a protuberanceextending therefrom and configured to be coupled to a drivinginstrument.
 33. The device of claim 32, wherein the protuberancecomprises a hex, a hexalobular, a threaded, or a square protuberance.34. The device of claim 10, wherein the upper endplate assemblycomprises a first endplate and a second endplate, and wherein the lowerendplate assembly comprises a third endplate and a fourth endplate. 35.The device of claim 34, wherein the ramp assembly comprises a firstproximal ramp and a second proximal ramp, and a first distal ramp and asecond distal ramp, and wherein at least one of the first endplate andthe second endplate, the third endplate and the fourth endplate, thefirst proximal ramp and the second proximal ramp, and the first distalramp and the second distal ramp have mirrored equivalence.
 36. Thedevice of claim 34, wherein at least one of the second endplate and thefourth endplate is larger than at least one of the first endplate andthe third endplate.
 37. The device of claim 34, wherein at least one ofthe exterior faces of the first end plate, the second endplate, thethird endplate, and the fourth endplate comprise a texture configured togrip the vertebrae.
 38. The device of claim 37, wherein the texturecomprises a tooth, a ridge, a roughened area, a metallic coating, aceramic coating, a keel, a spike, a projection, a groove, or anycombination thereof.
 39. The device of claim 10, wherein at least one ofthe actuator, the wedge assembly, the ramp assembly, the upper endplateassembly, and the lower endplate assembly comprise titanium, cobalt,stainless steel, tantalum, platinum, PEEK, PEKK, carbon fiber, bariumsulfate, hydroxyapatite, a ceramic, zirconium oxide, silicon nitride,carbon, bone graft, demineralized bone matrix product, synthetic bonesubstitute, a bone morphogenic agent, a bone growth inducing material,or any combination thereof.
 40. An expandable fusion system forimplantation between two adjacent vertebrae, the system comprising aninserter and the expandable fusion device of claim
 10. 41. The system ofclaim 40 further comprising a collapsing tool.